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Root-knot nematode Meloidogyne incognita is among the biotic factors which has greatly affected both the yield and the quality of the tomato crop. The egg parasitic nematode, Purpureocillium lilacinum (Pl) is considered as one of the most promising agents in controlling and overcoming this plant pathogen. The nematicidal effect of the native isolate Pl AUMC 10149 on second stage juvenile’s survival and egg hatching of M. incognita at different times of exposure was tested in vitro. The obtained data showed that Pl gave a maximum percentage of J2 mortality (97.6%) and egg hatching inhibition (79.8%) after 72 hours of exposure. The potentiality of Pl as well as Bio-Nematon to control M. incognita infecting tomato was conducted using different times of application in vivo. Nine treatments with five replicates were used for such bioagents compared with the nematicide Oxamyl. Each seedling was inoculated with 1000 J2s of nematode/pot and 10 mL of Pl (1x1010 CFU/mL) or Bio-Nematon spore suspension (1x108 CFU/mL) 10mL/pot. The results indicated that the most effective treatments in reducing nematode population, number of galls and egg masses of M. incognita in plant roots was performed with treatment by Pl pre-planting and post-infection with Pl (Rf 1.9) giving a significant enhancement in plant length (64.9%), fresh weight (72.52%) and shoot dry weight (163.41%) without negatively impacting environment. Therefore, the present study confirmed that using P. lilacinum AUMC 10149 can be used as a practical supplement to environmentally friendly disease management of root-knot nematodes in Egypt. Resumo O nematoide-das-galhas Meloidogyne incognita está entre os fatores bióticos que afetaram enormemente a produção e a qualidade da cultura do tomate. O nematoide parasita de ovos, Purpureocillium lilacinum (Pl), é considerado um dos mais promissores agentes no controle e superação desse fitopatógeno. O efeito nematicida do isolado nativo Pl AUMC 10149 na sobrevivência de juvenis de segundo estágio e na eclosão dos ovos de M. incognita em diferentes momentos de exposição foi testado in vitro. Os dados obtidos mostraram que o Pl deu um percentual máximo de mortalidade de J2 (97.6%) e inibição da eclosão dos ovos (79.8%) após 72 horas de exposição. A potencialidade de Pl e de Bio-Nematon para controlar M. incognita infectando tomate foi conduzida em diferentes tempos de aplicação in vivo. Nove tratamentos com cinco repetições foram usados para tais bioagentes em comparação com o nematicida Oxamyl. Cada muda foi inoculada com 1.000 J2s de nematoide / vaso e 10 mL de Pl (1×1010 CFU/mL). Ou suspensão de esporos Bio-Nematon (1×108 CFU/mL) 10mL/pot. Os resultados indicaram que os tratamentos mais eficazes na redução da população de nematoides, número de galhas e desovas de M. incognita nas raízes das plantas foram realizados com Pl pré-plantio e pós-infecção com Pl (Rf 1.9), dando um aumento significativo no comprimento da planta (64.9%), massa fresca (72.52%) e massa seca da parte aérea (163.41%) sem impactar negativamente o meio ambiente. Portanto, o presente estudo confirmou que o uso de P. lilacinum AUMC 10149 pode ser usado como um suplemento prático para o manejo ecologicamente correto de nematoides-das-galhas no Egito.

The bZIP transcription factor (TF) SlTGA2.2 was previously highlighted as a possible hub in a network regulating fruit growth and transition to ripening (maturation phase). It belongs to a clade of TFs well known for their involvement in the regulation of the salicylic acid–dependent systemic acquired resistance. To investigate if this TGA TF plays a role in tomato fruit growth and maturation, we took advantage of the fruit-specific SlPPC2 promoter (PPC2pro) to target the expression of a SlTGA2.2-SRDX chimeric repressor in a developmental window restricted to early fruit growth and maturation. Here, we show that this SlTGA2.2-SRDX repressor alters early fruit development and metabolism, including chloroplast number and structure, considerably extends the time necessary to reach the mature green stage and slows down fruit ripening. RNA sequencing and plant hormone analyses reveal that PPC2pro:SlTGA2.2-SRDX fruits are maintained in an immature stage as long as PPC2pro is active, through early modifications of plant hormonal signaling and down-regulation of MADS-RIN and NAC-NOR ripening regulators. Once PPC2pro becomes inactive and therefore SlTGA2.2-SRDX expression is reduced, ripening can proceed, albeit at a slower pace than normal. Altogether, this work emphasizes the developmental continuum between fruit growth, maturation and ripening and provides a useful tool to alter and study the molecular bases of tomato fruit transition to ripening.

Tomato (Solanum lycopersicum L.) plants are able to adapt to restrictive environmental conditions mainly due to hormones such as brassinosteroids (BRs) that play important roles in determining stomata conductance and leaf transpiration. However, BRs effects on morphological traits like stomata and trichome position, size, and density, as well as on physiological traits resulting in better plant water use efficiency (WUE) and productivity, remain poorly understood. The objective of this study was to better understand the 2,4-epibrassinolide (EBL) mechanisms regulating leaf transpiration and WUE that can affect fruit production in tomato plants. According to results, treating tomato plants with exogenous EBL resulted in lower leaf transpiration, mainly from 9 to 16 h during the day, as well as lower stomata conductance and aperture, higher leaf water potential, higher net CO2 assimilation rate, higher number of stomata and trichome on leaf abaxial and adaxial surfaces, and higher plant dry mass accumulation, which improved plant WUE, compared to non-treated plants. EBL treatment also increased fruit size, fruit production per plant, and fruit quality traits such as higher dry mass and soluble solids content. In conclusion, BRs can improve plant adaptation to water stress conditions by regulating important physiological and morphological mechanisms, controlling plant WUE, and leading to higher fruit production.

Insects are known plant pests, and some of them such as Trichoplusia ni feed on a variety of crops. In this study, Trichoplusia ni was fed distinct diets of leaves of Arabidopsis thaliana or Solanum lycopersicum as well as an artificial diet. After four generations, the microbial composition of the insect gut was evaluated to determine if the diet influenced the structure and function of the microbial communities. The population fed with A. thaliana had higher proportions of Shinella, Terribacillus and Propionibacterium, and these genera are known to have tolerance to glucosinolate activity, which is produced by A. thaliana to deter insects. The population fed with S. lycopersicum expressed increased relative abundances of the Agrobacterium and Rhizobium genera. These microbial members can degrade alkaloids, which are produced by S. lycopersicum. All five of these genera were also present in the respective leaves of either A. thaliana or S. lycopersicum, suggesting that these microbes are acquired by the insects from the diet itself. This study describes a potential mechanism used by generalist insects to become habituated to their available diet based on acquisition of phytochemical degrading gut bacteria.

A non-transgenic approach based on RNA interference was employed to induce protection against tomato mosaic virus (ToMV) infection in tomato plants. dsRNA molecules targeting the cp gene of ToMV were topically applied on plants prior to virus inoculation. Protection was dose-dependent and sequence-specific. While no protection was achieved when 0–16 µg dsRNA were used, maximum rates of resistance (60 and 63%) were observed in doses of 200 and 400 µg/plant, respectively. Similar rates were also obtained against potato virus Y when targeting its cp gene. The protection was quickly activated upon dsRNA application and lasted for up to 4 days. In contrast, no detectable antiviral response was triggered by the dsRNA from a begomovirus genome, suggesting the method is not effective against phloem-limited DNA viruses. Deep sequencing was performed to analyze the biogenesis of siRNA populations. Although long-dsRNA remained in the treated leaves for at least 10 days, its systemic movement was not observed. Conversely, dsRNA-derived siRNA populations (mainly 21- and 22-nt) were detected in non-treated leaves, which indicates endogenous processing and transport through the plant. Altogether, this study provides critical information for the development of novel tools against plant viruses; strengths and limitations inherent to the systems are discussed.

In Uruguay, the production of tomato (Solanum lycopersicum) in greenhouse presents pollination issues that limit its yield. The use of bumblebees (Bombus spp.) as pollinators can help overcome this problem as they perform “buzzing pollination”, a behavior that makes them excellent pollinators of Solanaceae and particularly tomato. The aim of this study was to evaluate the effect of the native bumblebees Bombus atratus on the proportion of fruit set, weight, diameter, number of seeds and number of locules of tomato (lapataia and elpida varieties). An experience was carried out in Canelones, where the fruits from flowers pollinated by bumblebees and from flowers not visited by insects were compared; two other experiences carried out in Salto were similar to that of Canelones, but included flowers treated with hormones. In the three analyzed greenhouses the visit of bumblebees to the flowers increased the proportion of fruit set by 13 - 47%, compared to the result obtained in flowers not visited by the insects. Also, the pollinating action of bumblebees significantly improved the weight, size, and number of seeds compared to fruits obtained from flowers without access to pollinators. This improvement was recorded in the experience in Canelones and only in one of the Salto's experiences. On the other hand, a positive correlation was found between the number of seeds and the weight (R2 = 0.37, R2 = 0.53; lapataia, elpida, respectively) in the two tomato varieties. This study is the first in Uruguay to show the benefits of using native bumblebees in tomato production in greenhouses. Resumen: En Uruguay, la producción de tomate (Solanum lycopersicum) bajo invernáculo presenta problemas de polinización que limitan su rendimiento. El uso de abejorros (Bombus spp.) como polinizadores puede contribuir a superar este problema, ya que realizan «polinización por zumbido», comportamiento necesario para polinizar las solanáceas y particularmente el tomate. El objetivo de este estudio fue evaluar el efecto de los abejorros nativos Bombus atratus en el porcentaje de cuajado, peso, diámetro, número de semillas y número de lóculos de tomate (variedades lapataia y elpida). Se realizó una experiencia en el departamento de Canelones donde se cotejaron los frutos de flores polinizadas por abejorros y flores no visitadas por los insectos; y dos experiencias en Salto iguales a la de Canelones, pero que incluían flores tratadas con hormonas. En los tres invernáculos la visita de los abejorros a las flores incrementó el porcentaje de cuajado entre 13 y 47 % en relación con el obtenido en flores no visitadas por los insectos. La acción polinizadora de los abejorros también mejoró significativamente el peso, tamaño y número de semillas respecto a frutos obtenidos de flores sin acceso a polinizadores en dos de las tres experiencias realizadas. Por otro lado, en las dos variedades de tomate se encontró una correlación positiva entre el número de semillas y el peso (R2=0,37, R2=0,53; lapataia, elpida, respectivamente). Este estudio es el primero en Uruguay que muestra los beneficios de utilizar abejorros nativos para mejorar la producción de tomates en invernáculos. Resumo: No Uruguai, a produção de tomate (Solanum lycopersicum) em estufas apresenta problemas de polinização que limitam sua produção. O uso de abelhas (Bombus spp.) como os polinizadores podem contribuir para superar esse problema, uma vez que realizam a "polinização por zumbido", um comportamento necessário para polinizar as máscaras e principalmente o tomate. O objetivo deste estudo foi avaliar o efeito da abelha nativa Bombus atratus (abelhão) sobre a porcentagem de frutos, peso, diâmetro, número de sementes e número de lóculos de tomate (variedades lapataia e elpida). Foi realizada uma experiência no departamento de Canelones, onde foram coletados os frutos de flores polinizadas por abelhas e as flores não visitadas por insetos; e duas experiências em Salto iguais às de Canelones, mas que incluíam flores tratadas com hormônios. Nas três estufas, a visita das abelhas às flores aumentou o conjunto de frutos entre 13 e 47% em relação ao obtido em flores não visitadas pelos insetos. A ação polinizadora das abelhas também melhorou significativamente o peso, tamanho e número de sementes em comparação aos frutos obtidos de flores sem acesso aos polinizadores em duas das três experiências realizadas. Por outro lado, nas duas variedades de tomate, foi encontrada uma correlação positiva entre o número de sementes e o peso (R2 = 0,37, R2 = 0,53; lapataia, elpida, respectivamente). Este estudo é o primeiro no Uruguai a mostrar os benefícios do uso de abelhas nativas para melhorar a produção de tomate em estufas.

Numerous studies have highlighted the merits of grafting to improve the performance of vegetable crops. However, the technique is hindered by several obstacles, including the synchronization of seedlings used as scions and rootstocks, and the effects of rootstocks and climatic conditions on grafting success rates. This study sought to gain insights into how such technical obstacles affect tomato grafting. An initial experiment conducted in a greenhouse set out to assess the relevance of using degree-days to predict the growth rates of seedlings used for grafting (i.e., stem diameters above cotyledons). The success rate for grafting a tomato variety (Tanya) on 10 different rootstocks from different species—namely tomato, eggplant, african eggplant, and a wild species—was assessed at different temperatures (i.e., 15, 20, 25, 30, 35, and 40 °C). The effects of grafting on plant vigor (i.e., fresh biomass), number of leaves, and plant height, and on the hydraulic conductivity of xylem vessels in the plant stem were assessed 2 weeks after grafting. The results show the advantage of using degree-days to predict the ready-to-graft stage of seedlings, as it reduced the discrepancy among trials. The grafting success rate was more than 90% at 15 and 20 °C, but decreased significantly with higher temperatures, down to 20% at 40 °C. Larger variations in growth rate for seedlings used as scions and rootstocks, a lower grafting success rate, and less vigor were recorded for heterografted plants than for homografted plants. The lower hydraulic conductivity measured in the stems of grafted plants, especially heterografted plants, was consistent with the lower plant vigor observed. Further studies are needed to investigate how grafting affects the hydraulic conductivity of xylem vessels in later developmental stages of grafted plants.

Microbial communities associated with plant leaf surfaces (i.e. the phyllosphere) are increasingly recognized for their role in plant health. While accumulating evidence suggests a role for host filtering of its microbiota, far less is known about how community composition is shaped by dispersal, including from neighboring plants. We experimentally manipulated the local plant neighborhood within which tomato, pepper, or bean plants were grown in a three-month field trial. Focal plants were grown in the presence of con- or hetero-specific neighbors (or no neighbors) in a fully factorial combination. At 30-day intervals, focal plants were harvested and replaced with a new age- and species-matched cohort while allowing neighborhood plants to continue growing. 16S community profiling revealed that the strength of host filtering effects (i.e. interspecific differences in composition) decreased over time. In contrast, the strength of neighborhood effects increased over time, suggesting dispersal from neighboring plants becomes more important as neighboring plant biomass increases. We next implemented a cross-inoculation study in the greenhouse using inoculum generated from the field plants to directly test host filtering of microbiomes while controlling for directionality and source of dispersal. This experiment further demonstrated that focal host species, the host from which the microbiome came, and in one case the donor hosts’ neighbors, contribute to variation in phyllosphere bacterial composition. Overall, our results suggest that local dispersal is a key factor in phyllosphere assembly, and that demographic factors such as nearby neighbor identity and biomass or age are important determinants of phyllosphere microbiome diversity.

Die Tomate (Solanum lycopersicum) ist eine wesentliche Kulturpflanze. RBOHs sind NADPH-Oxidasen, die ROS produzieren. Sie werden durch Phosphorylierung und Ca+2-Bindung reguliert. In der vorliegenden Arbeit wurden 13 CBLs und 27 CIPKs, die im Tomaten-Genom kodiert sind, mithilfe einer bioinformatischen Analyse erfolgreich identifiziert. Zusätzlich wurden 8 SlRBOHs identifiziert. Genetische, molekulare und biochemische Beweise zeigten, dass SlCIPK23 durch Wechselwirkung und Phosphorylierung als sicherer Regler der SlRBOHF-Aktivität dient. Darüber hinaus funktionieren die SlCBL1/SlCIPK23-Gene zusammen als positive Regulatoren der SlRBOHF-Aktivität. Außerdem zeigte eine amiRNA-vermittelte SlRBOHF Knockdown-Mutant infolge des Salzstress einen Wachstumshemmungsphänotyp und eine reduzierte ROS-Produktion. Ein weiterer interessanter Aspekt dieser Arbeit ist die Erkenntnis, dass die P2 eine hitzebeständige Tomatensorte ist. Tomato (Solanum lycopersicum) is a major crop plant. ROS and Ca+2 play a central role in responses to many abiotic stresses. RBOHs are NADPH oxidases that produce ROS. They are regulated by phosphorylation and Ca+2 binding. In this study, 13 CBLs and 27 CIPKs that are encoded in the tomato genome were successfully identified by using a bioinformatics analysis. Additionally, 8 SlRBOHs were identified. Genetic, molecular and biochemical evidences revealed that SlCIPK23 functions as a positive regulator of the SlRBOHF activity through interaction and phosphorylation. Moreover, the SlCBL1/SlCIPK23 genes together were functioning as positive regulators of SlRBOHF activity. Furthermore, an amiRNA- mediated SlRBOHF knock down mutant in response to salt stress displayed growth inhibition phenotype and reduced ROS production. Another interesting aspect of this work was revealed that the P2 is a heat tolerant tomato cultivar.

Made available in DSpace on 2022-04-28T19:42:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Universidade Federal do Rio Grande do Sul Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) is one of the main tomato pests in several countries, mainly in Africa, and applications of synthetic acaricides are the main strategy for its control. Efficient biopesticides to suppress pest populations, with low toxicity against natural enemies, is highly desirable for integrated pest management. Here, we evaluated under laboratory conditions the effect of azadirachtin- and oxymatrine-based formulations on each development stage of T. evansi and on the adult stage of the predatory mite Phytoseiulus longipes, the single promising predator of this pest. We also assessed the residual effect of these biopesticides on T. evansi under laboratory conditions on leaflets excised from treated tomato plants maintained in a screen-house 1, 5, and 10 days after application. Azadirachtin-based formulations were effective in controlling T. evansi immature stages. Oxymatrine-based treatments controlled T. evansi immatures and adult females faster than azadirachtin-based treatments. Both biopesticides had no effect on T. evansi eggs, but oxymatrine-based treatments were highly efficient on newly hatched T. evansi larvae. Oxymatrine displayed residual activity that controlled T. evansi up to 10 days after application. Azadirachtin formulations caused lower mortality of P. longipes adults (8-28%) and slightly reduced fecundity (24.8-56.1%). In contrast, oxymatrine treatments caused higher mortality (60-88%) of the predator and reduced substantiality its fecundity (73.1-90.7%). Our findings suggest that Azadirachtin and oxymatrine provide effective control of T. evansi. Azadirachtin may be relatively safer to the predatory mites whereas oxymatrine should be used with caution, to avoid suppression of P. longipes. Departamento de Ciências da Produção Agrícola Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista, SP Departamento de Entomologia e Acarologia Escola Superior de Agricultura “Luiz de Queiroz” Universidade de São Paulo, SP Faculté d'Agronomie Université de Parakou Departamento de Ciências da Produção Agrícola Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista, SP CNPq: 301492

A major issue in modern agriculture is water loss through stomata during photosynthetic carbon assimilation. In water-limited ecosystems, annual plants have strategies to synchronize their growth and reproduction to the availability of water. Some species or ecotypes of flowers are early to ensure that their life cycles are completed before the onset of late season terminal drought ("drought escape"). This accelerated flowering correlates with low water-use efficiency (WUE). The molecular players and physiological mechanisms involved in this coordination are not fully understood. We analyzed WUE using gravimetry, gas exchange, and carbon isotope discrimination in florigen deficient (sft mutant), wild-type (Micro-Tom), and florigen over-expressing (SFT-ox) tomato lines. Increased florigen expression led to accelerated flowering time and reduced WUE. The low WUE of SFT-ox was driven by higher stomatal conductance and thinner leaf blades. This florigen-driven effect on WUE appears be independent of abscisic acid (ABA). Our results open a new avenue to increase WUE in crops in an ABA-independent manner. Manipulation of florigen levels could allow us to produce crops with a life cycle synchronized to water availability.

O potencial fisiológico das sementes está diretamente relacionado à normalidade do processo de formação delas, sob ponto de vista morfológico, estrutural e funcional. Deste modo, o objetivo deste trabalho foi avaliar a morfologia interna de sementes de tomate, híbrido BRS Nagai, em diferentes estádios de maturação, por meio da análise de imagens de raios-X, relacionando com a germinação e o vigor das sementes. As sementes foram radiografadas tendo sido suas imagens analisadas para a classificação da morfologia do embrião e mensuração do espaço livre entre o embrião e endosperma, com auxílio do programa de análise de imagens ImageJ. Estes resultados foram comparados com a qualidade fisiológica através do teste de germinação. As correlações mostraram que as sementes possuidoras de embriões classificados como normais tendem a apresentar maior germinação, e produzir plântulas normais. E àquelas que possuem maior área livre interna tendem a apresentar ausência de germinação ou originarem maiores percentuais de plântulas anormais. A análise de imagens utilizando raios-X é eficiente para o estudo da maturidade fisiológica de sementes de tomate. A análise de raios-X pode predizer o desempenho das sementes por meio da morfologia do embrião, permitindo a seleção de sementes de alta qualidade. Sementes de tomateiro de frutos com até 40 dias após a polinização apresentam baixa qualidade morfofisiológica quando comparadas com sementes extraídas de frutos totalmente maduros, a partir dos 60 dias após a polinização. The seed physiological potential has been directly related to normal formation process under morphological, structural and functional point of view. The objective of this study was to evaluate the internal morphology of ‘BRS Nagai’ tomato hybrid seeds at different stages of development and maturation, through the X-ray image analysis and relate the results with the seed germination and vigor. Seeds were extracted from fruits harvested at 30, 40, 50, 60 and 70 days after pollination (DAP). Subsequently, seeds were x-rayed with their images analyzed visually for the embryo morphology classification; also, the measurement of clearance between the embryo and endosperm was performed with the help of the ImageJ software. These results were compared with the seed physiological quality by germination. The correlations involving the analysis of X-ray showed that the seeds have embryos classified as normal tend to have higher vigor and produce normal seedlings. On the other hand, seeds with higher internal free area tend to have low vigor and higher percentage of abnormal seedlings. The image analysis using X-rays is efficient for the study of physiological maturity of tomato seeds. The analysis of X-rays may predict seed performance by means of the embryo morphology, permitting the selection of high quality seeds. Tomato seeds of fruits with up to 40 days after pollination have low morphophysiological quality when compared to seeds extracted from fully mature fruits, from 60 days after pollination.

International audience; Ascorbate is a major antioxidant buffer in plants, so several approaches have been developed to increase the ascorbate contents of fruits and vegetables. In this study, we combined forward genetics with mapping-by-sequencing approaches using an EMSMicro-Tom population to identify putative regulators underlying a high ascorbate phenotype in fruits. Among the ascorbate-enriched mutants, the family with the highest fruit ascorbate level (P17C5 line, up to 5 times the WT) strongly impaired flower development and produced seedless fruit. Without progeny, genetic characterization was performed by outcrossing the P17C5 line with S. Lycopersicum cv. M82. We successfully identified the mutation responsible for the high ascorbate trait in a cis-acting upstream open reading frame (uORF) that is involved in the downstream regulation of GDP-L-galactose phosphorylase (GGP). Using a specific CRISPR strategy, we generated uORF-GGP1 mutants and confirmed the ascorbate-enriched phenotype. We further investigated the impact of the ascorbate-enrichment trait in tomato plants by phenotyping the original P17C5 EMS mutant, the population of outcrossed P17C5xM82 plants, and the CRISPR-mutated line. These studies revealed that a high ascorbate content is linked to impaired floral organ architecture, particularly anthers and pollen development, thus leading to male sterility. RNAseq analysis suggests that uORF-GGP1 acts as a regulator of ascorbate synthesis that maintains redox homeostasis to allow appropriate plant development.

Zoophytophagous plant bugs feed on plant tissue as a source of water and nutrients, besides feeding on prey. By phytophagy, mirid predators activate plant defense responses through different pathways, resulting, among others, in the release of herbivore‐induced plant volatiles (HIPVs). These compounds could repel herbivores and attract parasitoids and predators, and synthetic versions could potentially be used in biological control. Nevertheless, little is known about the influence of synthetic volatiles on mirid attraction. Using Y‐tube olfactometer trials, we evaluated the responses of Nesidiocoris tenuis (Reuter), Macrolophus pygmaeus (Rambur), and Dicyphus bolivari Lindberg (Hemiptera: Miridae), important natural enemies used to control various greenhouse pests, to 10 synthetic versions of HIPVs released from tomato (Solanum lycopersicum L., Solanaceae) plants induced by N. tenuis and M. pygmaeus. Nesidiocoris tenuis responded to five of the 10 HIPVs, whereas M. pygmaeus and D. bolivari responded to four of the 10 HIPVs. Two green leaf volatiles, (Z)‐3‐hexenyl propanoate and (Z)‐3‐hexenyl acetate, and the ester methyl salicylate (MeSA) were attractive to all three mirid predator species. Our results demonstrate that the volatiles released by tomato plants activated by N. tenuis and M. pygmaeus phytophagy are attractive to their conspecifics and also to D. bolivari. Further studies should evaluate the potential of these compounds to attract predatory mirids in the field.

Existen antecedentes de la reducción de daños por nemátodos con el uso de elicitores, compuestos que estimulan defensas en las plantas, promoviendo el metabolismo secundario. Este trabajo tuvo como objetivos evaluar la nematofauna presente en el suelo y raíces del cultivo antecesor, y medir el efecto sobre el rendimiento y daño en raíces por Nacobbus aberrans en tomate (Solanum lycopersicum)‘Elpida’, tratado por drench 24 horas previas al trasplante con 1 mL de ácido salicílico 0,50 x 10⁻⁴ M y 1,00 x 10⁻⁴ M, etileno 0,35 x 10⁻³ M y 0,70 x 10⁻³ M, ácido jasmónico 1,00 x 10⁻⁴ M y 1,00 x 10⁻⁵ M, dejando testigos sin tratar. En el suelo se identificaron nemátodos saprófitos, omnívoros y predatores, Helicotylenchus spp. y N. aberrans. El cultivo antecesor fue tomate ‘Elpida’ sin injertar e injertado sobre Maxifort, 9184, Multifort y Beaufort, identificándose huevos y N. aberrans J2 en todas las raíces, en cantidad significativamente menor en Maxifort y 9184. Las fitohormonas incrementaron la producción de frutos con peso mayor a 150 g y el rendimiento total respecto al testigo, produciendo menor número de agallas, índice de agallamiento y reproducción. Ácido salicílico 1,00 x 10⁻⁴ M produjo menor daño en raíces y mayor producción total y por racimos, seguido por etileno 0,70 x 10⁻³ M y ácido jasmónico 1,00 x 10⁻⁵ M. Es importante continuar investigando aspectos prácticos del uso de elicitores y profundizar en la comprensión de su acción para el control de N. aberrans., There is evidence that indicates that elicitors reduce damage caused by nematodes. Elicitors are compounds that stimulate plant defense promoting secondary metabolism. The aims of this study were to evaluate the soil and previous root crop nematofauna in tomato ‘Elpida’, and determine the effect on yield and root damage by Nacobbus aberrans. Soil drench applications were conducted 24 hours pre-transplanting with 1 mL of: salicilic acid 0.50 x 10⁻⁴ M and 1.00 x 10⁻⁴ M, ethylen 0.35 x 10⁻³ M and 0.70 x 10⁻³ M, jasmonic acid 1.00 x 10⁻⁴ M and 1.00 x 10⁻⁵ M, including untreated plants as control. In the soil, saprophytic, omnivorous and predatory nematodes, as well as Helicotylenchus spp. and N. aberrans, were identified. The previous crop was ungrafted ‘Elpida’ plants and also grafted on Maxifort, 9184, Multifort and Beaufort. Eggs and N. aberrans J2 were identified in all roots, with significantly lower amounts in Maxifort and 9184. Phytohormones increased the production of fruits with weight higher than 150 g and total yield compared to the control, producing lower galls, galling and reproductive indexes. Salicylic acid 1.00 x 10⁻⁴ M produced lower damage to the roots and a higher total yield and truss yield, followed by ethylene 0.70 x 10⁻³ M and jasmonic acid 1.00 x 10⁻⁵ M treatments. Further research is required to provide deeper knowledge of the practical implications of using elicitors and enhance the understanding of their action for N. aberrans control., Facultad de Ciencias Agrarias y Forestales, Facultad de Ciencias Naturales y Museo, Instituto de Fisiología Vegetal

The use of computational tools has become notable in seed quality control to assist in confirming seed lots of higher potential. Thus, the aim of this study was to use a computational approach to investigate analysis of morphological parameters that characterize primary root emergence in evaluation of tomato seed vigor. For that purpose, five seed lots were analyzed for germination and vigor (seedling emergence and analysis of seedling images). A parallel analysis of primary root emergence was made using computer-assisted imaging; the images recorded as germination proceeded were processed with the ImageJ® software to obtain aspect ratio and seed area parameters. Vigor differences among tomato seed lots can be identified based on primary root emergence, and computer image processing based on aspect ratio proves to be an efficient procedure to characterize emergence of the primary root in evaluation of tomato seed vigor. Resumo: A inclusão do uso de ferramentas computacionais no controle da qualidade de sementes tem-se destacado com o intuito de auxiliar em maior assertividade na caracterização de lotes de maior potencial. Assim, o objetivo deste estudo foi investigar por meio de uma abordagem computacional a análise de parâmetros morfológicos que caracterizem a emergência da raiz primária na avaliação do vigor de sementes de tomate. Para isso, cinco lotes de sementes foram analisados quanto a sua germinação e vigor (emergência de plântulas e análise de imagens de plântulas). Em paralelo, a emergência da raiz primária foi analisada utilizando visão computacional assistida; as imagens registradas durante o progresso de germinação foram processadas com o software ImageJ® para obtenção dos parâmetros de relação de aspecto e área da semente. As diferenças de vigor entre lotes de sementes de tomate podem ser identificadas com base na emergência da raiz primária e o processamento computacional das imagens baseado na relação de aspecto apresenta-se como um procedimento eficiente para a caracterização da emergência da raiz primária na avaliação do vigor de sementes de tomate.

Helicoverpa armigera (Hübner) regularly requires quick deployment of control practices due to its potential of causing yield loss of processing tomatoes. The monitoring of H. armigera adults using stick traps lured with sex pheromone was correlated to egg densities, larvae, and percentage of damaged fruits, aiming to subsidize control decisions only using the number of males caught in the traps since surveying pest stages or damaged fruits is laborious and costly. Surveys were carried out on 11 tomato fields (ca. 80 to 120 hectares each) for processing during the 2015 and 2016 crop seasons. The survey was initiated at the flowering stage with traps set up along the field borders 100 m distant each. Evaluations of adult male capture in the traps were conducted twice a week for 14 and 10 weeks during the 2015 and 2016 seasons, respectively. Simultaneously, 70 tomato plants were fully inspected for eggs, larvae, and damaged fruits per area using a rate of 10 plants per point of trap setting in each area. Overall capture of male moths correlated to subsequent eggs, larvae, and damaged fruits. Based on the outcome of the regression analysis between male moths captured and percentage of damaged fruits, the control decision is suggested when three to six male moths are captured per trap during one week. The monitoring of adults using pheromone traps help deploy chemical or biological control methods to restrain H. armigera population reaching economic threshold levels.

Both nitrogen and calcium fertilization management are vital for crops, where an imbalance of these elements can cause both physiological and yield problems. It has been proposed that nitrogen absorption, particularly ammonium, is in part dependent on calcium supply. Moreover, the balance between these two nutrients could be a key indicator of plant growth in some species. Tomato, one of the most cultivated crops worldwide, can also be widely affected by nutritional imbalance. Using large amounts of N fertilizers could lead to an imbalance with other nutrients and, thus, detrimental effects in terms of plant development and yield. Here we show that ammonium excess has a negative impact on plant development and results in calcium deficiency. Moreover, a deficit in calcium nutrition not only affects calcium concentration but also leads to a restriction in N uptake and reduced N concentration in the plant. These effects were evident at the seedling stage and also during flowering/fruit set. Using PCA analysis, we integrated both phenotypic and nutritional imbalances in seedlings and grown plants. Interestingly, the Ca/N ratio appears to be a key indicator to monitor appropriate N and calcium nutrition and more importantly the balance between both. Maintaining this balance could be an essential element for tomato crop production. Made available in DSpace on 2021-07-21T16:01:58Z (GMT). No. of bitstreams: 1 Ammonium-Excess-Leads-to-Ca-Restrictions-2021.pdf: 1980106 bytes, checksum: c6f77a850c31e9c1f3389cce0b48c0b7 (MD5) Previous issue date: 2021

The present study aimed to investigate the Cd-induced transgenerational effects on plants. Grafted tomato plants, which exhibited the same cultivar as scion and distinct cultivars with contrasting Cd-tolerance as rootstocks, were grown in soil without and with artificial addition of Cd (less than 2.0, and 6.9 mg kg-1 of Cd, respectively) in a pot experiment carried out in a greenhouse. Their fruits were harvested to extract seeds (i.e., the progenies), which were sown over either Cd-free (control) or Cd-containing germitest paper (germination testing paper with 0 and 35 μM of CdCl2, respectively) and grown in a growth chamber. The immediate progeny of all grafting combinations from stressed plants presented an elevated germinability, despite high internal Cd concentration. When sown in Cd-containing germitest paper, the immediate progeny of plants grown in soil with no Cd addition was generally able to maintain or even increase the content of carotenoids and chlorophylls a and b (up to 93.3, 62.8 and 76.1%, respectively), indicating a Cd-induced hormetic effect on photosynthetic pigments. Two of the grafting combinations from stressed plants yielded seeds that generated seedlings with enhanced dry mass when they were sown in Cd-free media (~41%), suggesting a Cd-induced transgenerational enhancement of biomass production. Because only one tomato cultivar was used as scion, data indicated that type and degree of Cd-induced transgenerational effects depend strongly on signals generated and/or processed in roots of the parental plants. When sown in Cd-contaminated germitest paper, the immediate progeny of Cd-treated plants presented major reductions in the leaf area (35-69%) and content of photosynthetic pigments (57-93%) in comparison to the progeny from control plants. However, one of the grafting combinations exhibited satisfactory performance after "double" exposure to Cd, showing 91% of the biomass that was produced in the seedlings of control seeds from control plants. Further investigation indicated that adjustments in the chlorophyll fluorescence behavior might counterbalance losses in leaf pigments and area. Taken together, our data provide new insights on the origin, outcomes and mode of action of the Cd-induced transgenerational effects.

Introducción: Bactericera cockerelli es un insecto que daña cultivos de solanáceas, principalmente papa (Solanum tuberosum L) y tomate (Solanum lycopersicum L). El manejo de B. cockerelli ha sido el control químico; sin embargo, se han tratado de implementar otras estrategias de control con insecticidas menos tóxicos para el medio ambiente, la salud humana e insectos no blanco. Esta implementación consiste en incluir organismos de control biológico como depredadores, parasitoides, insecticidas de origen natural y botánicos, hongos entomopatógenos e insecticidas químicos con menor impacto en fauna benéfica. Con el fin de profundizar en estas interacciones, el presente trabajo determinó la concentración letal media (CL50) de insecticidas sobre las poblaciones de B. cockerelli y su parasitoide Tamarixia triozae. Con estos datos se calculó el porcentaje de selectividad (PS) de los diferentes insecticidas con el parasitoide T. triozae.Método: Se realizaron bioensayos mediante el método de inmersión tratando de simular las aplicaciones de cobertura completa que se realizan en campo; se evaluaron seis insecticidas; Profenofos y Cipermetrina de origen organosintético; Azadiractina y AEC (Aceites esenciales de cítricos con canela y jabón de aceites vegetales) de origen botánicos; una cepa de Beauveria bassiana y otra de Metarhizium anisopliae. Con los datos obtenidos se determinó la selectividad utilizando la Proporción de Selectividad (PS), dividiendo la CL50 del producto sobre el enemigo natural entre la CL50 del producto sobre el insecto plaga, donde valores iguales o mayores a uno nos indica selectividad.Resultados: Los productos insecticidas evaluados mostraron mortalidad en B. cockerelli y su parasitoide T. triozae. La menor proporción de selectividad fue para Cipermetrina (PS = 0.01) y solo M. anisopliae mostró selectividad con T. triozae al obtener un valor de PS = 3.58. Los demás insecticidas mostraron valores de PS menores a uno por lo que se consideraron no selectivos para el parasitoide.Conclusión: Con base en los índices de selectividad, la letalidad hacia T. triozae fue mayor que a B. cockerelli. La mayor toxicidad fue en los insecticidas de origen organosintéticos, botánico y biológico en ese orden. La excepción fue la cepa de la especie Metarhizium anisopliae, que mostró selectividad (PS=3.58) hacia el parasitoide.

Reunir em um mesmo híbrido ampla resistência a pragas, maior produtividade e qualidade nutricional de frutos é um desafio de melhoristas de tomateiro tipo Salada. A utilização de uma linhagem anã na obtenção de híbridos poderia ser uma excelente alternativa para se alcançar tais objetivos, sendo uma estratégia de aumento de produtividade já conhecida para o segmento de Minitomates. Porém, a exploração dos benefícios proporcionados pelo uso do parental anão em híbridos de tomateiro tipo Salada ainda não é uma realidade. O desenvolvimento de linhagens anãs do referido segmento é a primeira etapa a ser realizada, sendo o retrocruzamento um método adequado para se desenvolver tais linhagens. Adicionalmente ao retrocruzamento, torna-se importante também avaliar o progresso das populações anãs obtidas após avanço no ciclo de autofecundações. Portanto, o objetivo deste trabalho foi selecionar populações F2RC1 e F3RC1 de tomateiro anão tipo Salada com potencial agronômico, qualidade de fruto e resistência a pragas. O trabalho foi realizado em duas etapas: primeiro estudou-se o desempenho de populações anãs obtidas após um retrocruzamento (F2RC1) e, em seguida, o desempenho de populações anãs obtidas após uma autofecundação (F3RC1) de plantas selecionadas em F2RC1. Ambos os experimentos foram conduzidos em casa de vegetação na Estação Experimental de Hortaliças da Universidade Federal de Uberlândia (UFU), Monte Carmelo. No primeiro experimento utilizou-se o delineamento de blocos casualizados com 15 tratamentos e três repetições. O material genético avaliado consistiu de 12 populações F2RC1 de tomateiro anão, os genitores (recorrente e doador) e um híbrido comercial. Concluiu-se que a massa média dos frutos das populações anãs aumentou significativamente após o primeiro retrocruzamento e algumas destas apresentaram o formato de fruto próximo ao do segmento Salada. Ao selecionar as populações UFU-DTOM3, UFU-DTOM5, UFUDTOM7, UFU-DTOM9 e UFU-DTOM10 foi estimado um incremento de até 6% no número de lóculos, diâmetro transversal, formato e massa média do fruto. As populações anãs UFU-DTOM7 e UFU-DTOM10 se destacaram sendo promissoras para obtenção de linhagens. Para o segundo estudo, o material genético avaliado consistiu de dez populações anãs F3RC1 originadas da autofecundação de plantas selecionadas em populações anãs F2RC1 os genitores (recorrente e doador) e um híbrido comercial. De maneira geral, houve um aumento de até 1035% na massa média dos frutos das populações anãs em relação ao genitor doador. Além disso, algumas populações anãs apresentaram frutos com 49% a mais de licopeno em comparação com o híbrido comercial, bem como maiores teores de acilaçúcares nas folhas (273%). A população anã UFU-DW22 se destacou, com potencial agronômico, maiores teores de licopeno nos frutos e também elevados teores de acilaçúcares, o que confere resistência a pragas. Para dar continuidade a trabalhos com as plantas anãs F3RC1 deste estudo, sugere-se realizar o segundo retrocruzamento para obter linhagens e, posteriormente, híbridos compactos provenientes de linhagens anãs do tipo Salada. Combine broad-spectrum pest resistance, higher yield and fruit nutritional quality on a single hybrid is a challenge for round tomato breeders. The use of a dwarf line to obtain mini-tomato hybrids has provided advantages and can be an excellent alternative to achieve these objectives in the round tomatoes. However, the exploitation of the benefits provided by the use of the dwarf parent in tomato round hybrids is not yet a reality. The development of dwarf lineages of this segment is the first step to be performed and backcrossing is an appropriate method to develop such lineages. In addition to backcrossing, it is also important to assess the progress of dwarf populations obtained after advancing in the self-fertilization cycle. Therefore, the objective of this work was to select BC1F2 and BC1F3 populations of dwarf tomato type round with agronomic potential, fruit quality and resistance to pests. This research was carry out in two stages: first, the performance of dwarf populations obtained after a backcross (BC1F2) and, then, the performance of dwarf populations obtained after a selffertilization (BC1F3) of plants from populations selected in BC1F2. Both trials were carried out at the vegetable trial station at the Federal University of Uberlandia – Monte Carmelo Campus, MG, Brazil. For the first experiment, was used a randomized block design with 15 treatments and 3 replications. The genetic material evaluated consisted of 12 dwarf tomato BC1F2 populations, plus both parents (recurrent and donor) and a commercial hybrid. It was observed that average fruit weight in the dwarf populations increased significantly after the first backcross, with some fruits exhibiting a similar shape to round tomatoes. Selection of the populations UFU-DTOM3, UFU-DTOM5, UFU-DTOM7, UFU-DTOM9 and UFU-DTOM10 resulted in an estimated 6% increase in the number of locules, transverse diameter, TD/LD ratio and average fruit weight. The dwarf populations UFU-DTOM7 and UFU-DTOM10 were the most promising for develop inbred lines with round fruits. For the second study, the genetic material evaluated consisted of ten BC1F3 dwarf populations, originated from self-fertilization of plants selected in dwarf populations BC1F2 plus both parents (recurrent and donor) and a commercial hybrid. In general, there was an increase of up to 1035% in the average fruit mass of the dwarf populations in relation to the donor parent. In addition, some dwarf populations showed fruits with 49% more lycopene in relation to the commercial hybrid, as well as higher levels of acylsugars in the leaves (273%). The dwarf populationUFU-DW22 stood out, presenting agronomic potential, higher levels of lycopene in fruits and high levels of acylsugars, which gives resistance to pests. In order to future work with the BC1F3 dwarf plants in this study, is suggest to perform the second backcross to obtain lines and, subsequently, compact hybrids from dwarf lines of the round type. Tese (Doutorado) 2022-10-01

Abastract: The interaction between Metarhizium spp. and plant roots may induce host plant growth and help control below- and above-ground pests and diseases. We conducted in vivo and in vitro bioassays using native Brazilian isolates of Metarhizium robertsii (ESALQ 1635), M. humberi (ESALQ 1638), and M. anisopliae (ESALQ 1669) to better understand the possible mechanisms related to plant growth promotion traits and colonization of the root system in the model pot-grown tomato (Solanum lycopersicum L.) miniature cultivar ?Micro-Tom.? In vivo trials revealed that M. robertsii (ESALQ 1635) or M. humberi (ESALQ 1638) inoculated in tomato seedlings improved vegetative and reproductive traits. Inoculation with M. robertsii yielded taller plants, longer roots, and more shoot and root dry mass than M. humberi. The number of flowers and the fresh weight of fruits was significantly increased by M. robertsii and M. humberi inoculation, in relation to uninoculated control plants. Both fungal species endophytically colonized all tomato tissues within 30 days of inoculation. Plants inoculated with either M. robertsii or M. humberi increased auxin-induced GUS expression in the roots for up to 30 days after inoculation, confirming that Metarhizium induces auxin-regulated gene expression. We also explored the production of key compounds including enzymes, hormones, and metabolites involved in plant growth promotion. The three Metarhizium species grown with or without exogenous tryptophan were able to produce indole-3-acetic acid (IAA) at different titers. All Metarhizium isolates produced phosphatases, phytases, siderophores, and chitinases. Of particular importance, the M. robertsii and M. humberi isolates exhibited similar in vitro biochemical profiles, whereas M. anisopliae and Trichoderma harzianum isolates demonstrated distinct traits from the others. Taken together, we argue that the M. robertsii isolate is more efficient than the M. humberi isolate to endophytically colonize tomato plants resulting in improved growth. However, M. humberi (ESALQ 1638) yielded a slightly better production of some metabolites in vitro. Thus, we propose that the isolates of M. robertsii and M. humberi could be explored as complementary plant growth promoters. Made available in DSpace on 2020-10-23T09:12:08Z (GMT). No. of bitstreams: 1 Mascarin-Multi-trait-biochemical-2020.pdf: 2330100 bytes, checksum: dfc48eeb89b590a67ff5dd669361578b (MD5) Previous issue date: 2020

El tomate (Solanum lycopersicum) es una de las hortalizas más consumidas en el mundo con un aumento en su demanda, por lo que conocer la viabilidad de sus semillas es de suma importancia, ya que estas son la base del éxito de su producción. Debido a esto, el presente estudio tuvo como objetivo optimizar la prueba de tetrazolio determinando el pretratamiento adecuado para potenciar la prueba. El material vegetal se recolectó de cultivos establecidos en el municipio del Cáchira, departamento de Norte de Santander, Colombia. Las semillas se extrajeron de los frutos maduros y, posteriormente, se expusieron a pretratramientos con hipoclorito de sodio y agua destilada durante 10 minutos, con tres concentraciones de 2, 3, 5- cloruro trifenil tetrazolio (0,25 %, 0,15 % y 0,10 %) y distintos tiempos de exposición (6 h, 12 h y 24 h). Los datos de viabilidad obtenidos se corroboraron mediante la prueba de germinación en toallas de papel húmedas. Los resultados de viabilidad más relacionados con la prueba de germinación se obtuvieron al emplear las concentraciones de 0,25 % y 0,15 %, utilizando tanto el pretratamiento con hipoclorito de sodio como la inmersión en agua destilada. Tomato (Solanum lycopersicum) is one of the most consumed vegetables worldwide with increasing demand. erefore, knowing its seeds viability is of utmost importance since these are the basis of their production success. Accordingly, the study aimed at optimizing the tetrazolium test by determining the appropriate pretreatment to enhance it. Plant material was collected from crops established in the municipality of Cáchira, department of Norte de Santander, Colombia. e seeds were extracted from ripe fruits and subsequently exposed to preconditioning with sodium hypochlorite and distilled water for 10 minutes, with three concentrations of 2,3,5-triphenyl tetrazolium chloride (0.25 %, 0.15 %, and 0.10 %) and different exposure times (6 h, 12 h, and 24 h). e viability data obtained were corroborated by the germination test on wet paper towels. e viability results with the highest correlation with the germination test were obtained using the 0.25 % and 0.15 % concentrations, and utilizing the preconditioning treatment with sodium hypochlorite as well as immersion in distilled water.

Vivipary, wherein seeds germinate prior to dispersal while still associated with the maternal plant, is an adaptation to extreme environments. It is normally inhibited by the establishment of dormancy. The genetic framework of vivipary has been well studied; however, the role of epigenetics in vivipary remains unknown. Here, we report that silencing ofMETHYLTRANSFERASE1(SlMET1) promoted precocious seed germination and seedling growth within the tomato (Solanum lycopersicum) epimutantColorless non-ripening(Cnr) fruits. This was associated with decreases in abscisic acid concentration and levels of mRNA encoding 9-cis-epoxycarotenoid-dioxygenase (SlNCED), which is involved in abscisic acid biosynthesis. Differentially methylated regions were identified in promoters of differentially expressed genes, includingSlNCED.SlNCEDknockdown also induced viviparous seedling growth inCnrfruits. Strikingly,Cnrripening reversion suppressed vivipary. Moreover, neitherSlMET1/SlNCED-virus-induced gene silencing nor transgenicSlMET1-RNA interference produced vivipary in wild-type tomatoes; the latter affected leaf architecture, arrested flowering, and repressed seed development. Thus, a dual pathway in ripening andSlMET1-mediated epigenetics coordinates the blockage of seed vivipary.Analysis of a unique tomato epiallele reveals an epigenetic pathway that, along with the ripening process, modulates vivipary in tomato fruits.

The influence of six greenhouse cover types on the development of the vegetative phase of cultivated tomato plants (Lycopersicon esculentum Mill.) was analyzed. The cover films were manufactured by extrusion - blow molding. Special emphasis was put on measuring root, stem and leaf length and dry matter content of the plants, the results of which were compared to those obtained from plants sown outdoors. As expected, the cultivated plants exhibited more vigorous growth when compared to that of the plants grown under free exposure. Films additivated with polymers allowing higher percentages of light transmission and haze determined higher greenhouse inner temperatures, which, in turn, promoted biomass production in the plantation. The presence of an infrared blocker in the plastic film formulations prevented the temperature inside the greenhouses from decreasing drastically below the outer temperature overnight. Additives such as the UV absorber SMARTLIGHT RL1000™ and the red pigment IRGALITE BASF® 2BP™, which increase the amount of red light received by the plants, thus modifying the R:RF ratio, were found to affect the morphology of the studied plants. Although the effect of photomorphogenesis is weak, a slight decrease in the length and area of the tomato leaves could be observed when the R:RF ratio was high. Resumen Se analizó la influencia de seis tipos de cobertura de invernadero en el desarrollo de la fase vegetativa de plantas de tomate cultivadas (Lycopersicon esculentum Mill.). Las películas de cubierta fueron fabricadas por extrusión - moldeo por soplado. Se hizo especial hincapié en medir la longitud de la raíz, el tallo y la hoja y el contenido de materia seca de las plantas, cuyos resultados se compararon con los obtenidos de plantas sembradas en el exterior. Como se esperaba, las plantas cultivadas mostraron un crecimiento más vigoroso en comparación con las plantas cultivadas bajo exposición libre. Las películas aditivadas con polímeros que permiten porcentajes más altos de transmisión de luz y neblina determinaron temperaturas interiores más altas en el invernadero, lo que, a su vez, promovió la producción de biomasa en la plantación. La presencia de un bloqueador infrarrojo en las formulaciones de películas plásticas impidió que la temperatura dentro de los invernaderos disminuyera drásticamente por debajo de la temperatura exterior durante la noche. Aditivos como el absorbente de rayos UV SMARTLIGHT RL1000 ™ y el pigmento rojo IRGALITE BASF® 2BP ™, que aumentan la cantidad de luz roja recibida por las plantas, modificando así la relación R: RF, afectaron la morfología de las plantas estudiadas. Aunque el efecto de la fotomorfogénesis es débil, se pudo observar una ligera disminución en la longitud y el área de las hojas de tomate cuando la relación R: RF era alta.

18 p.-4 fig.-3 tab., Trichoderma species are well known biocontrol agents that are able to induce responses in the host plants against an array of abiotic and biotic stresses. Here, we investigate, when applied to tomato seeds, the potential of Trichoderma strains belonging to three di erent species, T. parareesei T6,T. asperellum T25, and T. harzianum T34, to control the fully pathogenic strain Pseudomonas syringae pv. tomato (Pst) DC3000, able to produce the coronatine (COR) toxin, and the COR-deficient strain Pst DC3118 in tomato plants, and the molecular mechanisms by which the plant can modulate its systemic defense. Four-week old tomato plants, seed-inoculated, or not, with a Trichoderma strain,were infected, or not, with a Pst strain, and the changes in the expression of nine marker genes representative of salicylic acid (SA) (ICS1 and PAL5) and jasmonic acid (JA) (TomLoxC) biosynthesis,SA- (PR1b1), JA- (PINII and MYC2) and JA/Ethylene (ET)-dependent (ERF-A2) defense pathways,as well as the abscisic acid (ABA)-responsive gene AREB2 and the respiratory burst oxidase gene LERBOH1, were analyzed at 72 hours post-inoculation (hpi) with the bacteria. The significant increase obtained for bacterial population sizes in the leaves, disease index, and the upregulation of tomato genes related to SA,JA, ET and ABA in plants inoculated with Pst DC3000 compared with those obtained with Pst DC3118, confirmed the COR role as a virulence factor, and showed that both Pst and COR synergistically activate the JA- and SA-signaling defense responses, at least at 72 hpi.The three Trichoderma strains tested reduced the DC3118 levels to di erent extents and were able to control disease symptoms at the same rate. However, a minor protection (9.4%) against DC3000 was only achieved with T. asperellum T25. The gene deregulation detected in Trichoderma-treated plus Pst-inoculated tomato plants illustrates the complex system of a phytohormone-mediated signaling network that is a ected by the pathogen and Trichoderma applications but also by their interaction.The expression changes for all nine genes analyzed, excepting LERBOH1, as well as the bacterial populations in the leaves were significantly a ected by the interaction. Our results show that Trichoderma spp. are not adequate to control the disease caused by fully pathogenic Pst strains in tomato plants., This work was supported by the Spanish Government [Project RTI2018-099986-B-I00]; the European Regional Development Fund (FEDER) under the Regional Government of Castile and Leon support [Projects SA270P18 and CLU-2018-04]. MM-D was granted by the Program II of Postdoctoral Fellows of the University of Salamanca. The funding body was used for experimental supplies.

Changes in environmental temperature influence many aspects of plant metabolism; however, the underlying regulatory mechanisms remain poorly understood. In addition to their role in light perception, phytochromes (PHYs) have been recently recognized as temperature sensors affecting plant growth. In particular, in Arabidopsis thaliana, high temperature reversibly inactivates PHYB, reducing photomorphogenesis-dependent responses. Here, we show the role of phytochrome-dependent temperature perception in modulating the accumulation of isoprenoid-derived compounds in tomato (Solanum lycopersicum) leaves and fruits. The growth of tomato plants under contrasting temperature regimes revealed that high temperatures resulted in co-ordinated up-regulation of chlorophyll catabolic genes, impairment of chloroplast biogenesis, and reduction of carotenoid synthesis in leaves in a PHYB1B2-dependent manner. Furthermore, by assessing a triple phyAB1B2 mutant and fruit-specific PHYA- or PHYB2-silenced plants, we demonstrated that biosynthesis of the major tomato fruit carotenoid, lycopene, is sensitive to fruit-localized PHY-dependent temperature perception. The collected data provide compelling evidence concerning the impact of PHY-mediated temperature perception on plastid metabolism in both leaves and fruit, specifically on the accumulation of isoprenoid-derived compounds. Fil: Bianchetti, Ricardo E.. Universidade de Sao Paulo; Brasil Fil: de Luca, Maria Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: de Haro, Luis Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: Rosado, Daniele. Universidade de Sao Paulo; Brasil Fil: Demarco, Diego. Universidade de Sao Paulo; Brasil Fil: Conte, Mariana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentina Fil: Bermúdez, Luisa. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Agronomía; Argentina Fil: Freschi, Luciano. Universidade de Sao Paulo; Brasil Fil: Fernie, Alisdair R.. Max Planck Institute Of Molecular Plant Physiology; Alemania Fil: Michaelson, Louise. Rothamsted Research; Reino Unido Fil: Haslam, Richard P.. Rothamsted Research; Reino Unido Fil: Rossi, Magdalena. Universidade de Sao Paulo; Brasil Fil: Carrari, Fernando Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Agronomía; Argentina

In semiarid regions is important to use native strains best adapted to these environments to optimize plant-PGPR interaction. We aimed to isolate and characterize PGPR from roots and rhizosphere of a tomato crop, as well as studying the effect of its inoculation on tomato seedlings growth. We selected four strains considering their effectiveness of fixing nitrogen, solubilizing phosphate, producing siderophores and indole acetic acid. They belong to the genera Enterobacter, Pseudomonas, Cellulosimicrobium, and Ochrobactrum. In addition, we also analyzed the ability to solubilize Ca3(PO4)2, FePO4 and AlPO4 and the presence of one of the genes encoding the cofactor PQQ in their genome. Enterobacter 64S1 and Pseudomonas 42P4 showed the highest phosphorus solubilizing activity and presence of pqqE gene. Furthermore, in a tomato-based bioassay in speed-bed demonstrated that a sole inoculation at seedling stage with the strains increased dry weight of roots (49–88%) and shoots (39–55%), stem height (8–13%) and diameter (5–8%) and leaf area (22–31%) and were equal or even higher than fertilization treatment. Leaf nitrogen and chlorophyll levels were also increased (50–80% and 26–33%) compared to control. These results suggest that Enterobacter 64S1 and Pseudomonas 42P4 can be used as bio-inoculant in order to realize a nutrient integrated management. Fil: Pérez Rodriguez, María Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina Fil: Piccoli, Patricia Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina Fil: Anzuay, María Soledad. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Baraldi, Rita. Consiglio Nazionale delle Ricerche; Italia Fil: Neri, Luisa. Consiglio Nazionale delle Ricerche; Italia Fil: Taurian, Tania. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto; Argentina Fil: Lobato Ureche, Miguel Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina Fil: Segura, Diana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina Fil: Cohen, Ana Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina

Growth-promoting rhizobacteria are soil bacteria that inhabit the surrounding root, and are directly or indirectly involved in promoting plant growth and development. The productivity efficiency of these groups of microorganisms can be applied to planting crops, providing an interesting alternative for minimize the negative effects of water deficit. The objective of this study was to verify if the mechanism of growth promotion of the bacterium is similar to that promoted by polyethylene glycol (PEG) and to compare the possible effects of water stress on the tomato against the effects of inoculation of the bacterium Serratia sp. The methodology was based on in vitro bioassays using tomato (Solanum lycopersicum L.) seedlings, kept in a growth chamber with temperature of 25 °C and photoperiod of 12 hours. The results revealed that the promotion of tomato root growth by Serratia sp. is similar to that promoted by PEG 7%, differing significantly from the results found with different doses of indoleacetic acid (IAA). The promotion of root growth in tomatoes by Serratia sp. and PEG 7% partly indicates a physical effect, since the water restriction imposed by the PEG molecule decreases the water movement capacity, also observed by bacteria, when colonizing plant tissues and cells (biofilm) reducing the hydraulic conductivity of water through the root. Stimulation to promote root growth in tomatoes cannot be reproduced by auxin. Las rizobacterias que promueven el crecimiento son bacterias del suelo que habitan el ambiente de la raíz y están directa o indirectamente involucradas en la promoción del crecimiento y desarrollo de las plantas. La eficiencia de la productividad de estos grupos de microorganismos se puede aplicar a la plantación de cultivos, lo que constituye una alternativa interesante para minimizar los efectos negativos del déficit hídrico. El objetivo de este estudio fue verificar si el mecanismo para promover el crecimiento de bacterias es similar al promovido por el polietileno glicol (PEG) y comparar los posibles efectos del estrés hídrico en los tomates con los efectos de la inoculación de la bacteria Serratia sp. La metodología se basó en bioensayos in vitro utilizando plántulas de tomate (Solanum lycopersicum L.), mantenidas en una cámara de crecimiento con una temperatura de 25 °C y un fotoperíodo de 12 horas. Los resultados revelaron que la promoción del crecimiento de la raíz de tomate por Serratia sp. es similar al promovido por PEG al 7%, que difiere significativamente de los resultados encontrados con diferentes dosis de ácido indol-acético (AIA). La promoción del crecimiento de las raíces en tomate por Serratia sp. y PEG 7% indican parcialmente un efecto físico, ya que la restricción de agua impuesta por la molécula de PEG disminuye la capacidad de movimiento del agua, también observada por las bacterias, al colonizar tejidos y células vegetales (biopelícula), reduciendo la conductividad hidráulica del agua a través de desde la raíz La auxina no puede reproducir el estímulo para promover el crecimiento de las raíces en los tomates. As rizobactérias promotoras de crescimento são bactérias do solo que habitam o entorno da raiz, e estão direta ou indiretamente envolvidas na promoção do crescimento e desenvolvimento das plantas. A eficiência da produtividade desses grupos de microrganismos pode ser aplicada ao plantio de culturas, constituindo uma alternativa interessante, para minimizar os efeitos negativos do déficit hídrico. O objetivo deste estudo foi verificar se o mecanismo de promoção do crescimento da bactéria é semelhante ao promovido pelo Polietileno glicol (PEG) e comparar os possíveis efeitos do estresse hídrico no tomate com os efeitos da inoculação da bactéria Serratia sp . A metodologia foi baseada em bioensaios in vitro utilizando plântulas de tomate (Solanum lycopersicum L.), mantidas em câmara de crescimento com temperatura de 25 °C e fotoperíodo de 12 horas. Os resultados revelaram que a promoção do crescimento da raiz de tomate por Serratia sp. é semelhante ao promovido pelo PEG a 7%, diferindo significativamente dos resultados encontrados com diferentes doses de ácido indol-acético (AIA). A promoção do crescimento radicular em tomateiro por Serratia sp. e PEG 7% indicam parcialmente um efeito físico, uma vez que a restrição hídrica imposta pela molécula PEG diminui a capacidade de movimentação da água, também observada por bactérias, ao colonizar tecidos e células vegetais (biofilme), reduzindo a condutividade hidráulica da água através da raiz. O estímulo à promoção de crescimento radicular nos tomates não pode ser reproduzido pela auxina.

International audience; Cell fate maintenance is an integral part of plant cell differentiation and the production of functional cells, tissues, and organs. Fleshy fruit development is characterized by the accumulation of water and solutes in the enlarging cells of parenchymatous tissues. In tomato (Solanum lycopersicum), this process is associated with endoreduplication in mesocarp cells. The mechanisms that preserve this developmental program, once initiated, remain unknown. We show here that analysis of a previously identified tomato ethyl methanesulfonate-induced mutant that exhibits abnormal mesocarp cell differentiation could help elucidate determinants of fruit cell fate maintenance. We identified and validated the causal locus through mapping-by-sequencing and gene editing, respectively, and performed metabolic, cellular, and transcriptomic analyses of the mutant phenotype. The data indicate that disruption of the SlGBP1 gene, encoding GUANYLATE BINDING PROTEIN1, induces early termination of endoreduplication followed by late divisions of polyploid mesocarp cells, which consequently acquire the characteristics of young proliferative cells. This study reveals a crucial role of plant GBPs in the control of cell cycle genes, and thus, in cell fate maintenance. We propose that SlGBP1 acts as an inhibitor of cell division, a function conserved with the human hGBP-1 protein.

Tomato (Solanum lycopersicum L.) grown in the state of Sao Paulo represents 21.5 % of the total production in Brazil, making it the top table tomato-producing state in the country. Tomato cultivation in greenhouses is becoming increasingly popular in Brazil, as crop plants are protected against pests and unfavorable weather. However, issues regarding elevated greenhouse temperatures are common and can severely impact tomato yield due to the deregulation of vital plant functions, leading to the generation of toxic reactive oxygen species (ROS) and oxidative stress. Since endogenous proline accumulation has been correlated with heat stress relief due to ROS elimination and protection of cell structures, we evaluated the effects of foliar applications of l -proline at rates ranging from 0 to 1600 mg L−1 onto photosynthetic parameters, antioxidant system enzymes, malonaldehyde and hydrogen peroxide contents, post-harvest characteristics, and productivity of tomato plants subjected to high temperatures during the growth cycle. Regardless of rate, l -proline applications resulted in lower hydrogen peroxide contents despite no increase in antioxidant enzymes´ activity, and improved titratable acidity (TTA) as well as the overall fraction of average total soluble solids (TSS) by TTA (i.e. TSS/TTA). l -proline applied at 50 and 100 mg L−1 increased commercial and total fruit yield per plant. The 100 mg L−1 rate also enhanced the plants´ water use efficiency while decreasing malonaldehyde content, further indicating that exogenous applications of l -proline at the optimal rate of 100 mg L−1 can aid in alleviating high temperature-related damage to greenhouse-grown tomato plants.

Soil predatory mites feed on a diverse diet making them excellent candidates for conservation biocontrol. Free-living nematodes (FLN) are commonly found in soils and serve as prey for many acarine predators. Our goal was to determine whether conservation biological control of plant-parasitic nematodes by predators could be enhanced by provisioning FLN with their culture medium (FLNCM) under semi-field conditions. We conducted two experiments on dwarf tomato plants, the first until the beginning of flowering and the second until harvest. The treatments evaluated were with and without: 1) the root-knot nematode Meloidogyne incognita, 2) the predator Stratiolaelaps scimitus, and 3) the FLN Rhabditella axei in its culture medium. In both experiments, gall abundance was lowest in the combined treatment of FLN and predators. Similar reduction in gall abundance occurred when only predators or only FLNCM was added to the soil mix. Additionally, in the FLNCM treatment, foliar macronutrients N and K were significantly higher than the negative control. Our original aim was to use FLN as a supplementary food source for predators in conservation IPM. Based on the significant reduction in gall numbers, and the increase in foliar macronutrients, it is clear that the FLNCM treatment played additional roles. Finally, for demonstration, the predation of M. incognita was visualized in high resolution imaging using a low-temperature-scanning electron microscope. Accordingly, we recommend that future research focus on identifying soil amendments that will foster the establishment of beneficial microbiota, FLN and soil predators for the conservation biological control of soil pests.

This work aimed to evaluate the nitrogen transfer, the yield and the nutrient contents of organic cherry tomatoes intercropped with legumes in two successive years. The randomized block experimenta...

The mechanisms of Aluminum (Al) tolerance are dependent on the plant species and genotypes, but the results attributed to the toxic effect of Al can also be influenced by pH. Our aim was to study the effect of Al and pH in the antioxidative system of two tomato genotypes in response to Al in hydroponic system. The genotypes Moneymaker (MM) and Calabash Rouge (CR) were grown in Hoagland and Arnon (1950) nutrient solution pH 6.0 until the complete establishment in hydroponic system. Then the plants were transferred to the treatments: minimum medium at pH 4.2, minimum medium at pH 6.5 and minimum medium pH 4.2 + 20 mmol L−1 AlCl3.6H2O. The sampling of plant material was performed in the times: zero (immediately before exposure to the treatments), 24 and 48 h after their beginning. Aluminum accumulation in MM roots was higher than in CR after 48 h. The highest hydrogen peroxide (H2O2) concentration was observed in the shoots at control and at low pH without Al in the roots of CR. Malondialdehyde (MDA) concentration in CR roots did not present alteration along the 48 h, remaining near or below the control, whereas genotype MM presented a lower MDA concentration after 48 h in the presence of Al in relation to CR. In the roots of the genotype CR, superoxide dismutase (SOD) activity was lower at pH 4.2+Al and higher at pH 4.2. We evidenced that the antioxidative system seems more involved in response to low pH than Al toxicity, and that genotype CR presents mechanisms of Al tolerance possibly more related to the lower Al translocation from roots to shoots than with the protective activity of antioxidant enzymes.

The cultivation of vegetables under tunnels is considered a promising alternative to the use of chemicals to manage insect pests. However, higher temperatures under covers hinder their use in warm regions. We investigated the effect of high tunnels covered with plastic film or small or large mesh insect-nets on the performances of tomato plants in Tanzania over two years. Control plants were grown in open field plots. The temperature during the day was 4°C and 15°C higher under the nets and under the plastic than in the open. The total number of insect pests per plant over the season was generally lower under the nets than in open, with the small mesh better than the large mesh. The nets promoted plant growth compared with the open plots, with higher leaf area, plant dry weight, and plant height. Marketable yields were lower in open (2.7 and 10.8 t.ha−1), intermediate under the large mesh (7.9 and 38.4 t.ha−1), and high under the small mesh (16.8 and 50.1 t.ha−1). Higher productivity under the nets was associated with better plant growth and fewer insects than in the open. Contrasting results could be obtained in warmer climates because of the increase in temperatures recorded under tunnels.

Tomato plants can be attacked by several diseases. The early blight disease causes large losses to tomato growers and requires many applications of fungicide for its control. Thus, the objective of this work was to evaluate the effect of saprobic fungi filtrates on the control of early blight (Alternaria solani) in tomato plants. The treatments consisted of fungi filtrates (Stachylidium bicolor - SBI; Periconia hispidula - PHI; Brachysporiella pulchra - BPU; Myrothecium leucotrichum - MLE; and Pycnoporus sanguineus - PSA) diluted at 20%, a control (water), and acibenzolar-S-methyl (ASM). Tomato plants with five leaves were treated with the filtrates, and A. solani was inoculated after three days. The variables analyzed were: area under the disease progress curve (AUDPC), and specific activity of the enzymes: catalase, lipoxygenase, peroxidase, and polyphenol oxidase. The SBI filtrate decreased the AUDPC in 80% for the third leaf and 96% for the fourth leaf. Catalase activity increased due to the application of BPU and PHI filtrates, at 96 hours post-inoculation (hpi). Lipoxygenase activity increased in 130%, 72%, 130%, and 81% at 24 hpi when applying the SBI, PHI, MLE, and ASM filtrates, respectively. The application of SBI, BPU, MLE, and PSA filtrates increased lipoxygenase activity in 30%, 26%, 12%, and 22%, respectively, at 120 hpi. Peroxidase activity increased 74% at 120 hpi, when applying the SBI filtrate. Polyphenol oxidase activity was not affected by the treatments. S. bicolor filtrate is efficient to control the severity of the early blight disease in tomato plants. RESUMO O tomateiro pode ser atacado por diversas doenças, como a pinta preta, que causa grandes prejuízos aos produtores, exigindo grande número de aplicações de fungicidas. Assim, o objetivo deste trabalho foi avaliar o efeito de filtrados de fungos sapróbios no controle de pinta preta do tomateiro (Alternaria solani). Os tratamentos foram constituídos por filtrados de Stachylidium bicolor (SBI), Periconia hispidula (PHI), Brachysporiella pulchra (BPU), Myrothecium leucotrichum (MLE) e Pycnoporus sanguineus (PSA) diluídos a 20%, além da testemunha (água) e acibenzolar-S-metil (ASM). As plantas de tomate, com cinco folhas, foram pulverizadas com filtrados e três dias após realizou-se a inoculação com A. solani. As variáveis analisadas foram a área abaixo da curva de progresso da doença (AACPD) e a atividade específica de catalase, lipoxigenases, peroxidase e polifenoloxidase. A aplicação de filtrado de SBI promoveu redução de 80% e 96% da AACPD na terceira e quarta folha respectivamente. A catalase foi incrementada com uso dos filtrados de BPU e PHI 96 hpi. A lipoxigenase foi incrementada 130, 72, 130 e 81% no horário 24 hpi ao aplicar os filtrados de SBI, PHI, MLE e ASM respectivamente. Os filtrados de SBI, BPU, MLE e PSA incrementaram a atividade da lipoxigenase em 30, 26, 12 e 22% respectivamente, no horário 120 hpi. A atividade de peroxidase aumentou 74% em função da aplicação de SBI 120 hpi. A polifenoloxidase não foi influenciada pelos tratamentos. O filtrado de S. bicolor é efetivo em promover o controle da severidade da pinta preta do tomateiro.

The oxidant/antioxidant balance affects the ripening time of tomato fruit. Ripening of tomato fruit is associated with several modifications such as loss of cell wall firmness and transformation of chloroplasts to chromoplasts. Besides a peak in H2O2, reactive oxygen species (ROS) are observed at the transition stage. However, the role of different components of oxidative stress metabolism in fruit ripening has been scarcely addressed. Two GDP-l-galactose phosphorylase (GGP) Solanum lycopersicum L. cv Micro-Tom mutants which have fruit with low ascorbic acid content (30% of wild type) were used in this work to unravel the participation of ascorbic acid and H2O2 in fruit maturation. Both GGP mutants show delayed fruit maturation with no peak of H2O2; treatment with ascorbic acid increases its own concentration and accelerates ripening only in mutants to become like wild type plants. Unexpectedly, the treatment with ascorbic acid increases H2O2 synthesis in both mutants resembling what is observed in wild type fruit. Exogenous supplementation with H2O2 decreases its own synthesis delaying fruit maturation in plants with low ascorbic acid content. The site of ROS production is localized in the chloroplasts of fruit of all genotypes as determined by confocal microscopy analysis. The results presented here demonstrate that both ascorbic acid and H2O2 actively participate in tomato fruit ripening., Instituto de Fisiología Vegetal

Translation initiation factors 4E (eIF4E) are the main source of resistance to potyvirus. We systematically assessed tomato single and double knock-out (KO) mutants of members of the eIF4E-coding gene family for resistance to Pepper veinal mottle virus (PVMV), a major constraint to tomato production. We show that the KO mutant of eIF4E2 has partial resistance to PVMV isolate IC, with plants harboring weak symptoms and low virus loads at the systemic level. The causal effect of eIF4E2 loss-of-function on resistance was confirmed on a progeny segregating for the KO mutation. The eIF4E2 KO mutant was resistant to six of the eight PVMV isolates tested and no resistance to other potyviruses was observed. This is the first evidence that mutation of eIF4E2 is in itself conferring resistance to a potyvirus and 3D protein modelling suggests that the eIF4E2 gene could be converted into a functional resistance allele.

Blossom-end rot (BER) is a physiological disorder that can affect 100% of the fruit crop depending on the genotype. Tomato varieties with elongated fruit usually have a greater susceptibility to BER than other varieties. To evaluate and identify the possible physiological and morphological characteristics related to the onset of BER development, four varieties of long-shape tomato fruit with different susceptibility to BER: ‘San Marzano,’ ‘Banana Legs,’ ‘Roma,’ and ‘Mini-Roma’ were examined. Our results show that ‘San Marzano’ and ‘Banana Legs’ (elongated fruit) had a higher incidence of BER and lower Ca2+ concentration in the distal fruit tissue. ‘San Marzano’ (the most elongated fruit) presented higher electrolyte leakage in the distal fruit tissue. By comparison, ‘Roma’ and ‘Mini-Roma’ (less elongated fruit) were less susceptible to BER and had a higher ratio for proximal/distal fruit Ca2+ and a lower distal cell-wall bound content of Ca2+. Additionally, xylem functionality (vessels transporting water and solutes) in the distal fruit tissue was also higher in these more-tolerant varieties. These results support the theory that total fruit content of Ca2+ is not the only factor determining fruit susceptibility to BER, but rather a balance between physiological and morphological factors that influence Ca2+ transport and allocation in the fruit.

Breeding of crops over millennia for yield and productivity1 has led to reduced genetic diversity. As a result, beneficial traits of wild species, such as disease resistance and stress tolerance, have been lost2. We devised a CRISPR–Cas9 genome engineering strategy to combine agronomically desirable traits with useful traits present in wild lines. We report that editing of six loci that are important for yield and productivity in present-day tomato crop lines enabled de novo domestication of wild Solanum pimpinellifolium. Engineered S. pimpinellifolium morphology was altered, together with the size, number and nutritional value of the fruits. Compared with the wild parent, our engineered lines have a threefold increase in fruit size and a tenfold increase in fruit number. Notably, fruit lycopene accumulation is improved by 500% compared with the widely cultivated S. lycopersicum. Our results pave the way for molecular breeding programs to exploit the genetic diversity present in wild plants.

[EN] Plants are sessile organisms that must perceive and respond to various environmental constraints throughout their life cycle. Among these constraints, drought stress has become the main limiting factor to crop production around the world. Water deprivation is perceived primarily by the roots, which efficiently signal the shoot to trigger drought responses in order to maximize a plant's ability to survive. In this study, the tomato (Solanum lycopersicum L.) mutant procera (pro), with a constitutive response to gibberellin (GA), and its near isogenic line cv. Micro-Tom (MT), were used in reciprocal grafting under well-watered and water stress conditions to evaluate the role of GA signaling in root-to-shoot communication during drought stress. Growth, oxidative stress, gene expression, water relations and hormonal content were measured in order to provide insights into GA-mediated adjustments to water stress. All graft combinations with pro (i.e. pro/pro, MT/pro and pro/MT) prevented the reduction of growth under stress conditions without a reduction in oxidative stress. The increase of oxidative stress was followed by upregulation of SlDREB2, a drought-tolerance related gene, in all drought-stressed plants. Scions harboring the pro mutation tended to increase the abscisic acid (ABA) content, independent of the rootstock. Moreover, the GA sensitivity of the rootstock modulated stomatal conductance and water use efficiency under drought stress, indicating GA and ABA crosstalk in the adjustment of growth and water economy., The Sao Paulo Research Foundation (FAPESP) for doctoral fellowship to the first author under grant 2014/19165-2.

RESUMEN La Septoriosis y Mancha bacteriana son consideradas enfermedades foliares importantes por reducir hasta 60% la producción del tomate, siendo limitantes principales para la producción sostenible. A fin de encontrar alternativas de control, se evaluó el efecto del extracto de Ka’a He’ẽ sobre la severidad de la Septoriosis y Mancha bacteriana, y promoción de crecimiento del tomate, realizando dos experimentos en la FCA-UNA, entre julio y diciembre de 2015. En el experimento 1 se determinó el contenido de clorofila, área foliar, altura, longitud radicular y masa seca, utilizándose cinco tratamientos y cuatro repeticiones que consistieron en dosis de 50, 150 y 300 mL L-1 del extracto de Ka’a He’ẽ, testigo absoluto y testigo químico. En el experimento 2 se determinó la severidad de la Septoriosis y Mancha bacteriana, rendimiento y °Brix de frutos, se utilizaron seis tratamientos y tres repeticiones que consistieron en dosis crecientes del extracto, mezcla del extracto con producto químico, testigo absoluto y testigo químico. Para ambos experimentos se empleó el diseño experimental Completamente al Azar. Los datos obtenidos fueron sometidos al ANAVA por el Test de Tukey. Los resultados indican que, la dosis baja del extracto de Ka’a He’ẽ redujo la severidad de la Septoriosis, aumentó el área foliar, altura, longitud radicular y masa seca, la dosis media redujo la severidad de la Mancha bacteriana y la dosis alta incrementó el contenido de clorofila además del rendimiento del cultivo. Así también, la mezcla con el producto químico aumentó los °Brix y disminuyó la severidad de las enfermedades foliares. ABSTRACT Septoria and Bacterial Spot Leaf are considered the most preponderant diseases due to reduction of 60% on tomato production, being the major constraints to sustainable production. In order to find control alternatives, it has been evaluated the effect of Ka’a He’ẽ extract on the severity of Septoria and Bacterial Spot Leaf, and the promotion of tomato growth performing two experiments at the FCA-UNA, conducted between July and December 2015. Experiment 1 was held to determine the content of chlorophyll, leaf area, height, root length and dry mass. It was applied 5 treatments with 4 replicates, on dose of 50, 150 and 300 mL L-1 of Ka’a He’ẽ extract, with an absolute control and a chemical one. On Experiment 2 it was quantified the severity caused by Septoria and Bacterial Spot on crop yield and °Brix of fruits. It was applied 6 treatments and 3 repetitions with increasing doses of the extract, and extract mix with chemical product, with an absolute control and chemical one. For both experiments, randomized block design was used. Obtained data was submitted to ANAVA, though Tukey test. The results indicate that the low doses of Ka’a He’ẽ extract present less severity of Septoria, increased leaf area, height, root length and dry mass of the plants. Medium doses decreased Bacterial Spot, while high doses increased chlorophyll content as well as crop yield. Moreover, extract combination with chemical product increased °Brix and decreased leaf diseases severity.

S.G., J.C., C.H.M. and P.J.G.M.d.W. were financially supported by a grant from the Royal Netherlands Academy of Sciences.; Fungal biotrophy is associated with a reduced capacity to produce potentially toxic secondary metabolites (SMs). Yet, the genome of the biotrophic plant pathogen Cladosporium fulvum contains many SM biosynthetic gene clusters, with several related to toxin production. These gene clusters are, however, poorly expressed during the colonization of tomato. The sole detectable SM produced by C. fulvum during in vitro growth is the anthraquinone cladofulvin. Although this pigment is not detected in infected leaves, cladofulvin biosynthetic genes are expressed throughout the pre-penetration phase and during conidiation at the end of the infection cycle, but are repressed during the biotrophic phase of tomato colonization. It has been suggested that the tight regulation of SM gene clusters is required for C. fulvum to behave as a biotrophic pathogen, whilst retaining potential fitness determinants for growth and survival outside its host. To address this hypothesis, we analysed the disease symptoms caused by mutant C. fulvum strains that do not produce or over-produce cladofulvin during the biotrophic growth phase. Non-producers infected tomato in a similar manner to the wild-type, suggesting that cladofulvin is not a virulence factor. In contrast, the cladofulvin over-producers caused strong necrosis and desiccation of tomato leaves, which, in turn, arrested conidiation. Consistent with the role of pigments in survival against abiotic stresses, cladofulvin protects conidia against UV light and low-temperature stress. Overall, this study demonstrates that the repression of cladofulvin production is required for C. fulvum to sustain its biotrophic lifestyle in tomato, whereas its production is important for survival outside its host.

Plant metabolites are important to world food security due to their roles in crop yield and nutritional quality. Here we report the metabolic profile of 300 tomato accessions (Solanum lycopersicum and related wild species) by quantifying 60 primary and secondary metabolites, including volatile organic compounds, over a period of 2 yr. Metabolite content and genetic inheritance of metabolites varied broadly, both within and between different genetic groups. Using genotype information gained from 10 000 single nucleotide polymorphism markers, we performed a metabolite genome-wide association mapping (GWAS) study. We identified 79 associations influencing 13 primary and 19 secondary metabolites with large effects at high resolution. Four genome regions were detected, highlighting clusters of associations controlling the variation of several metabolites. Local linkage disequilibrium analysis and allele mining identified possible candidate genes which may modulate the content of metabolites that are of significant importance for human diet and fruit consumption. We precisely characterized two associations involved in fruit acidity and phenylpropanoid volatile production. Taken together, this study reveals complex and distinct metabolite regulation in tomato subspecies and demonstrates that GWAS is a powerful tool for gene-metabolite annotation and identification, pathways elucidation, and further crop improvement.

In vitro and screen house experiments were conducted to investigate the effectiveness of thirteen phytochemicals from Artemisia elegantissimia and A. incisa on root knot nematode, Meloidogyne incognita in tomato (Lycopersicon esculentum L.) cv. Rio Grande. A positive control (Carbofuran) and negative control (H2O) were also used for comparison. Effectiveness of phytochemicals against juveniles (J2s) mortality and egg hatch inhibition were evaluated after 24, 48 and 72 hours of incubation at three concentrations viz; 0.1, 0.2 and 0.3 mg/mL in vitro conditions. Amongst thirteen phytochemicals, Isoscopletin (Coumarin), Carbofuran and Apigenin (Flavonoid) showed the highest mortality and egg hatch inhibition of M. incognita at all intervals. Inhibition of eggs and J2s mortality were the greatest (90.0%) and (96.0%) at 0.3 mg/mL concentration. Application of phytochemicals caused reduction in number of galls, galling index, and egg masses on tomato plant and enhanced plant growth parameters under screen house conditions. Gall numbers (1.50), galling index (1.00), number of juveniles (4.83) and egg masses (4.00) were greatly reduced and plant growth parameters such as; plant height (28.48 cm), fresh (72.13 g) and dry shoot weights (35.99 g), and root fresh (6.58 g) and dry weights (1.43 g) were increased significantly by using Isoscopletin. In structure activity relationship, juveniles of M. incognita, exhibited variations in their shape and postures upon death when exposed to different concentrations of phytochemicals of Artemisia spp. The present study suggests that Artemisia based phytochemicals possess strong nematicidal effects and can be used effectively in an integrated disease management program against root knot nematodes. Resumo Experimentos in vitro e de triagem foram conduzidos para investigar a eficácia de treze constituintes fitoquímicos de Artemisia elegantissimia e A. incisa no nematóide de galhas, Meloidogyne incognita em tomateiro (Lycopersicon esculentum L.) cv. Rio Grande. Um controle positivo (carbofuran) e controle negativo (H2O) também foram utilizados para comparação. A eficácia dos fitoquímicos contra a mortalidade juvenil (J2s) e a inibição da eclosão de ovos foram avaliadas após 24, 48 e 72 horas de incubação em três concentrações, tais como: 0,1; 0,2 e 0,3 mg/mL em condições in vitro. Dentre os treze fitoquímicos, isoscopletina (cumarina), carbofurano e apigenina (flavonoide) apresentaram a maior mortalidade e a inibição da eclosão de ovos de M. incognita em todos os intervalos. A inibição da mortalidade dos ovos e J2s foi a maior (90,0%) e (96,0%) na concentração de 0,3 mg/mL. A aplicação de fitoquímicos causou redução no número de galhas, índice de fricção e massa de ovos no tomateiro e melhorou os parâmetros de crescimento das plantas em condições de triagem. Números de galhas (1,50), índice de insetos galhadores (1,00), número de juvenis (4,83) e massas de ovos (4,00) foram bastante reduzidos e os parâmetros de crescimento das plantas, como altura da planta (28,48 cm), peso fresco (72,13 g) e seco (35,99 g), raiz fresca (6,58 g) e peso seco (1,43 g) foram significativamente aumentados usando isoscopletina. Na relação atividade estrutura, juvenis de M. incognita, exibiram variações em sua forma e posturas após a morte quando expostos a diferentes concentrações de fitoquímicos de Artemisia spp. O presente estudo sugere que os fitoquímicos à base de artemísia possuem fortes efeitos nematicidas e podem ser usados eficazmente em um programa integrado de controle de doenças contra nematóides de galhas.

It is clearly established that there is not a unique response to soil water deficit but that there are as many responses as soil water deficit characteristics: Drought intensity, drought duration, and drought position during plant cycle. For a same soil water deficit, responses can also differ on plant genotype within a same species. In spite of this variability, at least for leaf production and expansion processes, robust tendencies can be extracted from the literature when similar watering regimes are compared. Here, we present response curves and multi-scale dynamics analyses established on tomato plants exposed to different soil water deficit treatments. Results reinforce the trends already observed for other species: Reduction in plant leaf biomass under water stress was due to reduction in individual leaf biomass and areas whereas leaf production and specific leaf area were not affected. The dynamics of leaf expansion was modified both at the leaf and cell scales. Cell division and expansion were reduced by drought treatments as well as the endoreduplication process. Combining response curves analyses together with dynamic analyses of tomato compound leaf growth at different scales not only corroborate results on simple leaf responses to drought but also increases our knowledge on the cellular mechanisms behind leaf growth plasticity.

Parthenocarpy arises when an ovary develops into fruit without pollination/fertilization. The mechanisms involved in genetic parthenocarpy have attracted attention because of their potential application in plant breeding and also for their elucidation of the mechanisms involved in early fruit development. We have isolated and characterized a novel small parthenocarpic fruit and flower (spff) mutant in the tomato (Solanum lycopersicum) cultivar Micro-Tom. This plant showed both vegetative and reproductive phenotypes including dwarfism of floral organs, male sterility, delayed flowering, altered axillary shoot development, and parthenocarpic production of small fruits. Genome-wide single nucleotide polymorphism array analysis coupled with mapping-by-sequencing using next generation sequencing-based high-throughput approaches resulted in the identification of a candidate locus responsible for the spff mutant phenotype. Subsequent linkage analysis and RNA interference-based silencing indicated that these phenotypes were caused by a loss-of-function mutation of a single gene (Solyc04g077010), which encodes a receptor-like protein kinase that was expressed in vascular bundles in young buds. Cytological and transcriptomic analyses suggested that parthenocarpy in the spff mutant was associated with enlarged ovarian cells and with elevated expression of the gibberellin metabolism gene, GA20ox1. Taken together, our results suggest a role for Solyc04g077010 in male organ development and indicate that loss of this receptor-like protein kinase activity could result in parthenocarpy.

The genetic basis of an erectoid leaf phenotype was investigated in distinct tomato breeding populations, including one derived from Solanum lycopersicum ‘LT05’ (with the erectoid leaf phenotype and uniform ripening, genotype uu) × S. pimpinellifollium ‘TO-937’ (with the wild-type leaf phenotype and green fruit shoulder, genotype UU). The erectoid leaf phenotype was inherited as a semi-dominant trait and it co-segregated with the u allele of gene SlGLK2 (Solyc10g008160). This genomic location coincides with a previously described semi-dominant mutation named as Erectoid leaf (Erl). The genomes of ‘LT05’, ‘TO-937’, and three other unrelated accessions (with the wild-type Erl+ allele) were resequenced with the aim of identifying candidate genes. Comparative genomic analyses, including the reference genome ‘Heinz 1706’ (Erl+ allele), identified an Erectoid leaf-specific single nucleotide polymorphism (SNP) in the gene Solyc10g009320. This SNP caused a change of a glutamine codon (present in all the wild-type genomes) to a TAA (= ochre stop-codon) in the Erl allele, resulting in a smaller version of the predicted mutant protein (221 vs. 279 amino acids). Solyc10g009320, previously annotated as an ‘unknown protein’, was identified as a TILLER ANGLE CONTROL1-like gene. Linkage between the Erl and Solyc10g009320 was confirmed via Sanger sequencing of the PCR amplicons of the two variant alleles. No recombinants were detected in 265 F2 individuals. Contrasting S7 near-isogenic lines were also homozygous for each of the alternate alleles, reinforcing Solyc10g009320 as a strong Erl candidate gene and opening the possibility for fine-tuning manipulation of tomato architecture in breeding programs.

A survey of viral diseases was carried out during 2012 to 2013 in two major tomato (Solanum lycopersicum L.) producing regions in Uruguay (Salto and Canelones). Lower leaves of fruit-bearing plants were observed displaying yellowing and interveinal chlorosis under greenhouse conditions. The symptoms were similar to those associated with magnesium deficiency. However, the chlorosis displayed a tendency to move up affecting medial and apical leaves and prevailed even after supplementary magnesium applications to the soil, indicating potential infection by either Tomato chlorosis virus (ToCV) or Tomato infectious chlorosis virus (TICV) (3). Four leaf samples were collected from two sites in Canelones and 28 samples were collected from distinct commercial fields in Salto. Whiteflies (Bemisia tabaci biotype Q and Trialeurodes vaporariorum) were present in all sampling sites. Total RNA was extracted from symptomatic and healthy (control) plants and used for cDNA preparation with the HS-11/HS-12 primer pair followed by PCR amplification using the same primer pair. The 587-bp amplicon, corresponding to a highly conserved region of the heat shock protein (HSP-70) homolog gene reported in both TICV and ToCV genomes, was observed only in the symptomatic samples. These PCR products were then subjected to nested PCR using the ToCV specific primer pair (ToC-5/ToC-6) and TICV specific primer pair (TIC-3/TIC-4) (1). The expected 463-bp ToCV-specific amplicon was observed in all symptomatic plants but not in the healthy controls. The 223-bp amplicon corresponding to TICV was not observed in any sample, indicating the sole presence of ToCV. The amplicon of one Uruguayan ToCV isolate from Salto (named as CRS03) was purified and directly sequenced (GenBank KC626018). BLAST analysis revealed 99% identity of CRS03 with one Spanish isolate (AF233435.1) (2). Virus-free B. tabaci biotype Q adults were exposed to symptomatic plants infected with the CRS03 isolate for a 24-h period and then cage-confined with 10 healthy tomato plants (line ‘LT17’) for a 48-h period. Symptoms were reproduced in all tested plants after a 65-day period and ToCV infection was confirmed via PCR assays and by sequence analysis of the gel-purified amplicons. This is the first formal report of ToCV infecting tomatoes in Uruguay. Incidence of symptomatic plants in tomato crops varied from 30 to 100%, even under low whitefly pressure. Epidemiological information needs to be generated in order to evaluate the impact of ToCV in the fresh-market tomato yield and quality. References: (1) C. I. Dovas et al. Plant Dis. 86:1345, 2002. (2) G. Lozano et al. Arch. Virol. 151:581, 2006. (3) G. C. Wisler et al. Arch. Virol. 151:409, 2006.