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Plant pathologies significantly jeopardise global food security, necessitating the development of prompt and precise diagnostic methods. This study employs advanced deep learning techniques to evaluate the performance of nine convolutional neural networks (CNNs) in identifying a spectrum of phytosanitary issues affecting the foliage of Solanum lycopersicum (tomato). Ten thousand RGB images of leaf tissue were subsampled in training (64%), validation (16%), and test (20%) sets to rank the most suitable CNNs in expediting the diagnosis of plant disease. The study assessed the performance of eight well-known networks under identical hyperparameter conditions. Additionally, it introduced the GamaNNet architecture, a custom-designed model optimised for superior performance on this specific type of dataset. The investigational results were most promising for the innovative GamaNNet and ResNet-152, which both exhibited a 91% accuracy rate, as evidenced by their confusion matrices, ROC curves, and AUC metrics. In comparison, LeNet-5 and ResNet-50 demonstrated lower assertiveness, attaining accuracies of 74% and 69%, respectively. GoogLeNet and Inception-v3 emerged as the frontrunners, displaying diagnostic preeminence, achieving an average F1-score of 97%. Identifying such pathologies as Early Blight, Late Blight, Corynespora Leaf Spot, and Septoria Leaf Spot posed the most significant challenge for this class of problem.

Abstract This study employed two prevalent plastic products - straws and microfiber as microplastics (MPs) to elucidate their largely unexplored effects on soil’s properties and the growth of the tomato plant (Solanum lycopersicum L.). For this experiment, a completely randomized design (CRD) was adopted where, straw - polypropylene (PP), microfiber - polyester (PES) + polyamide (PA), and their combinations (PP + PES + PA) were mixed with soil using different concentrations – 0% (control), 0.4%, 1%, and 2% (treatments) and kept for 45 days at room temperature. The findings demonstrated that incorporating 2% mixed MPs in soil significantly decreased bulk density and electrical conductivity 7.29% and 67.3%, respectively, while soil pH increased 17.84% in cultures containing 1% microfiber. Maximum water holding capacity (MWHC), soil organic carbon (SOC), and soil organic matter (SOM) showed varied responses based on MPs type and concentration. Specifically, MWHC increased 16.4% with 2% microfiber but declined 13.3% with 0.4% straw. The highest decreased (30.65%) in SOC and SOM were evident in cultures with 1% microfiber whereas increased 9.68% and 8.33% in cultures with 0.4% straw. In terms of the growth traits of S. lycopersicum, substantial reductions in plant height (56.37%), leaf number (54.37%), and girth diameter (56.43%) were observed in 2% straw containing cultures. Although no plant mortality was noted, the most pronounced reductions in leaf area (62.44%) and total plant biomass (68.16%) occurred in 2% microfiber cultures. Therefore, the ramifications of these findings may contribute to a deeper comprehension of the mechanisms and effects of MPs on soil properties and above-ground plant growth.

Abstract Climate change is one of the biggest challenges to the world at present. Tomato is also suffered from devastating yield loss due to climate change. The domesticated tomato (Solanum lycopersicum) is presumed to be originated from the wild tomato (S. pimpinellifolium). In this study, we compared the climate data of S. pimpinellifollium with the domesticated tomato, predicted the suitable regions of S. pimpinellifollium in China using MaxEnt model and assessed their tolerance to drought stress. We found that the predicted suitable regions of wild tomato are highly consistent with the current cultivated regions of domesticated tomato, suggesting that the habitat demand of domesticated tomato descended largely from its ancestor, hence the habitat information of wild tomato could provide a reference for tomato cultivation. We further predicted suitable regions of wild tomato in the future in China. Finally, we found that while average drought tolerance between wild and domesticated tomato accessions shows no difference, tolerance levels among wild tomato accessions exhibit higher variation, which could be used for future breeding to improve drought resistance. To summarize, our study shows that suitable regions of wild tomato provide insights into domesticated tomato cultivation in China.

Among the many biotic factors with adverse effects on Solanum lycopersicum (tomato), diseases caused by fungi, viruses and nematodes are notable. Since the genome of S. lycopersicum became available, efforts have continued to identify the genes and proteins associated with the plant defence activity. One such gene family belongs to TIR-NBS-LRR (TNL), a subfamily of larger NBS-LRR genes. In total, 27 full-length TNLs were identified via genome wide analysis. Four pairs of segmental duplication events were observed involving different pairs of chromosomes, except the pairing of Solyc02g082050-Solyc02g032650, which were both present on chromosome 2. More than twenty nine percent (29.63%) of the genes were localised on chromosome 1 alone. Hormone-mediated biotic stress-responsive cis-regulatory elements were detected for methyl-jasmonate, salicylic acid (TCA motif) and ethylene (ERE motif). Differential gene expression was observed for many genes under different plant tissues and biotic stresses. The upregulation of many genes including SlBS4 was observed against Alternaria solani attacks in the disease tolerant varieties. Altogether, the results suggested that TNLs play a significant role in plant defence under biotic stress.

During the survey of open tomato fields in Vojvodina (Serbia), characteristic anthracnose disease symptoms, including black, circular, sunken, and watery lesions, were observed in about 20% of fruits in September 2018. Subsequent pathogen isolations formed white aerial mycelia and numerous spherical, black conidiomata on the Potato Dextrose Agar. Ten representative isolates produced hyaline, smooth-walled, cylindrical, and aseptate conidia. The presence of initially brownish necrotic lesions on the tomato, which later expanded into large rotted areas, ultimately leading to complete fruit rot, confirmed the pathogenicity of the tested isolates. Molecular identification was performed using Bayesian analysis of concatenated ITS, TUB2, CHS-1, and ACT loci. Based on the combination of the morphological and molecular features, the fungus Colletotrichum nigrum was identified as the causal pathogen. As this is the first report on this fungal pathogen on tomatoes in Serbia, it highlights the importance of early and accurate detection for effective disease prevention, thus reducing crop damage and market losses.

Background: To counteract soil degradation, it is important to convert conventional agricultural practices to environmentally sustainable management practices. To this end, the application of biostimulants could be considered a good strategy. Compost, produced by the composting of biodegradable organic compounds, is a source of natural biostimulants, such as humic acids, which are naturally occurring organic compounds that arise from the decomposition and transformation of organic residues, and compost tea, a compost-derived liquid formulated produced by compost water-phase extraction. This study aimed to determine the molecular responses of the roots of tomato plants (cv. Crovarese) grown under hydroponic conditions and subjected to biostimulation with humic substances (HSs) and filtered sterile compost tea (SCT). Results: The 13C CPMAS NMR of humic acids (HA) and SCT revealed strong O-alkyl-C signals, indicating a high content of polysaccharides.Thermochemolysis identified over 100 molecules, predominantly from lignin, fatty acids, and biopolymers. RNA-Seq analysis of tomato roots treated with HA or SCT revealed differentially expressed genes (DEGs) with distinct patterns of transcriptional reprogramming. Notably, HA treatment affected carbohydrate metabolism and secondary metabolism, particularly phenylpropanoids and flavonoids, while SCT had a broader impact on hormone and redox metabolism. Both biostimulants induced significant gene expression changes within 24 h, including a reduction in cell wall degradation activity and an increase in the expression of hemicellulose synthesis genes, suggesting that the treatments prompted proactive cell wall development. Conclusions: The results demonstrate that HS and SCT can mitigate stress by activating specific molecular mechanisms and modifying root metabolic pathways, particularly those involved in cell wall synthesis. However, gene regulation in response to these treatments is complex and influenced by various factors. These findings highlight the biostimulatory effects of HS and SCT, suggesting their potential application in crop biofertilization and the development of innovative breeding strategies to maximize the benefits of humic substances for crops. Further research is needed to fully elucidate these mechanisms across various contexts and plant species. [ABSTRACT FROM AUTHOR]

SUMMARY: Type 2C protein phosphatases (PP2Cs) are emerging as important regulators of plant immune responses, although little is known about how they might impact nucleotide‐binding, leucine‐rich repeat (NLR)‐triggered immunity (NTI). We discovered that expression of the PP2C immunity‐associated candidate 14 gene (Pic14) is induced upon activation of the Pto/Prf‐mediated NTI response in tomato. Pto/Prf recognizes the effector AvrPto translocated into plant cells by the pathogen Pseudomonas syringae pv. tomato (Pst) and activate a MAPK cascade and other responses which together confer resistance to bacterial speck disease. Pic14 encodes a PP2C with an N‐terminal kinase‐interacting motif (KIM) and a C‐terminal phosphatase domain. Upon inoculation with Pst‐AvrPto, Pto/Prf‐expressing tomato plants with loss‐of‐function mutations in Pic14 developed less speck disease, specifically in older leaves, compared to wild‐type plants. Transient expression of Pic14 in leaves of Nicotiana benthamiana and tomato inhibited cell death typically induced by Pto/Prf and the MAPK cascade members M3Kα and Mkk2. The cell death‐suppressing activity of Pic14 was dependent on the KIM and the catalytic phosphatase domain. Pic14 inhibited M3Kα‐ and Mkk2‐mediated activation of immunity‐associated MAPKs and Pic14 was shown to be an active phosphatase that physically interacts with and dephosphorylates Mkk2 in a KIM‐dependent manner. Together, our results reveal Pic14 as an important negative regulator of Pto/Prf‐triggered immunity by interacting with and dephosphorylating Mkk2. [ABSTRACT FROM AUTHOR]

The Mi-1.2 gene confers resistance to a wide range of Meloidogyne species, being the most important resistance factor employed in tomato breeding so far. However, many aspects related to the interaction of Mi-1.2-carrying tomato cultivars and virulent/avirulent Meloidogyne populations have not yet been clarified. Herein, comparative histopathological analyses were carried after inoculation of the homozygous (Mi-1.2/Mi-1.2) tomato rootstock 'Guardião' and the susceptible cultivar 'Santa Clara' (mi-1.2/mi-1.2) with virulent and avirulent populations of M. javanica. In the susceptible control, it was possible to visualize second stage juveniles (J2) of avirulent population and feeding sites from 2 to 30 days after infection (DAI) with females reaching maturity at 24-34 DAI. In the resistant rootstock, the Mi-1.2 gene-mediated resistance was related mainly to early defense responses (pre-infection and hypersensitive reaction), which led to an immunity-like phenotype that completely prevented the reproduction of the avirulent Meloidogyne population. On the other hand, J2s of the virulent M. javanica population were able to penetrate roots much more than the avirulent population, migrated and developed normally, showing intense and similar pattern of penetration from 4 to 34 DAI in the root tissues of both resistant and susceptible tomato genotypes. The total numbers of J2, J3, J4, and females counted in 'Santa Clara' for the virulent population of M. javanica were higher than in 'Guardião'. [ABSTRACT FROM AUTHOR]

The use of microbial seed priming may be a promising tool to improve the first stages of seed germination of several herbaceous species. In tomatoes (Solanum lycopersicum L.), enhanced germination and vigor, and biotic and abiotic stress control, with a reduction in chemicals, have been reported. In this study, seeds from two Italian tomato varieties (Canestrino di Lucca and Pisanello) were primed with seven different strains of plant growth-promoting rhizobacteria (PGPB) belonging to Azospirillum baldaniorum, A. brasilense, Methylobacterium symbioticum, Bacillus amyloliquefaciens, B. licheniformis, and B. subtilis. They were selected for their ability to produce auxin. The germination test was carried out on treated seeds and the germination percentage was calculated. The obtained seedlings were transplanted and kept in greenhouse conditions. After 60 d, fresh and dry weight, root number, and length of plantlets were recorded. A general and significant improvement in the growth parameters was observed in the treated plants. All microbial strains proved to be indolacetic acid (IAA) producers using the Salkowsky method. A positive relationship between root number and length, and amount of IAA was found. The overall results suggest that the microbial priming of tomato seed could be useful for advancing organic farming, sustainable agriculture, and environmental protection. [ABSTRACT FROM AUTHOR]

Plant pathologies significantly jeopardise global food security, necessitating the development of prompt and precise diagnostic methods. This study employs advanced deep learning techniques to evaluate the performance of nine convolutional neural networks (CNNs) in identifying a spectrum of phytosanitary issues affecting the foliage of Solanum lycopersicum (tomato). Ten thousand RGB images of leaf tissue were subsampled in training (64%), validation (16%), and test (20%) sets to rank the most suitable CNNs in expediting the diagnosis of plant disease. The study assessed the performance of eight well-known networks under identical hyperparameter conditions. Additionally, it introduced the GamaNNet architecture, a custom-designed model optimised for superior performance on this specific type of dataset. The investigational results were most promising for the innovative GamaNNet and ResNet-152, which both exhibited a 91% accuracy rate, as evidenced by their confusion matrices, ROC curves, and AUC metrics. In comparison, LeNet-5 and ResNet-50 demonstrated lower assertiveness, attaining accuracies of 74% and 69%, respectively. GoogLeNet and Inception-v3 emerged as the frontrunners, displaying diagnostic preeminence, achieving an average F1-score of 97%. Identifying such pathologies as Early Blight, Late Blight, Corynespora Leaf Spot, and Septoria Leaf Spot posed the most significant challenge for this class of problem. [ABSTRACT FROM AUTHOR]

Most of the tomato (Solanum lycopersicum) varieties currently used in organic farming were bred for conventional farming, often characterized by high-input use. These varieties do not perform as well in low-input organic systems, generating the need to develop varieties that are adapted to organic management systems. This project focused on improving flavor, disease resistance, and yield, all identified as key traits by organic tomato farmers in the Upper Midwest, USA. Ten advanced tomato breeding lines and two check varieties were developed and evaluated for 16 traits in organic high tunnel systems in 2020 and 2021. The line CSDE-F6.47 averaged 6.32 kg/plant and obtained high flavor intensity and overall flavor scores (3.78 and 3.69 out of 5, respectively). The line JBDE-F5.31 was another outstanding line, with a yield of 5.18 kg/plant, with good flavor intensity (3.32) and overall flavor (2.92) scores. Broad-sense heritability of marketable weight per plant was high (0.91), and the genetic variance was also high, which shows the opportunity to continue to increase the marketable weight in lines with excellent flavor. A significant positive correlation was found between overall flavor and °Brix (0.56), and titratable acidity (0.70), indicating that both measurements can be good predictors of overall flavor. The most promising lines will be further evaluated on-farm to evaluate their potential as releasable varieties. [ABSTRACT FROM AUTHOR]

The sweet potato whitefly, Bemisia tabaci MED (Gennadius) (Hemiptera: Aleyrodidae), is highly harmful to solanaceous crops. The use of essential oils (EOs) is promising for the management of several insect pests, promoting both lethal and sublethal effects. This study aimed to evaluate the effects of sublethal concentrations of Pelargonium graveolens L'Her (Geraniaceae) EO on the feeding behavior of B. tabaci MED on tomato plants (Solanum lycopersicum L., Solanaceae). For this research, the electrical penetration graph (EPG) technique was used to monitor whitefly stylet activities on their host plants. Two sets of plants were previously sprayed with two concentrations of EO (the LC25 and LC50, which were determined in a mortality test), a third set was treated with the insecticide cyantraniliprole, and a fourth set received a control treatment. Our results indicate that the insecticide cyantraniliprole and the EO could both reduce the stylet feeding activity of B. tabaci MED, as well as reduce the number and duration of phloem sap ingestion events (waveform E2), which could avoid or reduce the transmission of viruses. Thus, the application of sublethal concentrations of P. graveolens EO, as well as exposure to cyantraniliprole, negatively affected the feeding behavior of B. tabaci MED. This information may contribute to the management of this pest and the reduction of the incidence of viruses in tomato production. [ABSTRACT FROM AUTHOR]

Global exploration of nanoparticles as nano-fertilizers/nano-fungicides to optimize crop production has attracted greater attention. Among metal oxide nano-formulations, the increasing application and discharge of copper oxide nanoparticles (CuO-NPs) into the environment requires urgent attention due to their toxic and stimulatory impact on plants, including vegetables. This study aimed at the bio-fabrication of CuO-NPs from Rosa indica petal extracts and to assess their nanotoxicity on germination and biological and biochemical growth of tomato plants. The morphological characterization of phytofabricated CuO-NPs by microscopic (SEM/TEM) and spectroscopic (XRD/FTIR) techniques revealed its nanostructure, spherical shape ranging in size between 23 and 47 nm exhibiting different functional groups. Furthermore, tomato-CuO-NPs interactions resulted in reduced germination percentage and plant biomass. At the biochemical level, the chlorophyll content decreased consistently, while malonaldehyde and proline content in tomato foliage enhanced substantially with increasing concentrations of CuO-NPs. Size, lycopene content (71 % reduction), and fruit quality (metabolites like sugars, amino acids, and organic acids) assessed by 1H NMR declined after CuO-NPs exposure in a dose-dependent manner. Further in situ experiments revealed deformation in a stomatal aperture in leaves and accumulation of CuO-NPs in roots, suggesting toxicity under SEM. In summation, this study highlights the toxicity of biosynthesized CuO-NPs to tomato plants paving the way to develop novel strategies to mitigate its toxicity to vegetable crops, particularly tomato under real field conditions. [Display omitted] • Copper oxide nanoparticles (CuO-NPs) exhibit toxic and stimulatory effects on plants. • Biogenic synthesized CuO-NPs from Rosa indica petal extract shows phytotoxicity to tomato plants. • Exposure to CuO-NPs reduces germination percentage, plant biomass, and fruit quality. • Metal oxide nanoparticles increase malondialdehyde and proline content after CuO-NPs exposure. • Strategies need to be developed to counteract nano-CuO toxicity. [ABSTRACT FROM AUTHOR]

Water limits may have a disastrous impact on agricultural productivity, and the current climate change scenario presents additional problems for crops that rely on regular rainfall. Reactive oxygen species, such as hydrogen peroxide (H2O2), are a recognized stress-sensing mechanism in plants, and may be investigated as an approach for reducing stress impact via systemic acquired acclimation. Here, we looked at how H2O2 foliar application impacts tomato plants' photosynthetic activity, antioxidant system, sugar chemical profile, and osmotic adjustment during drought and recovery. The experiment was in randomized blocks, 3 × 2 factorial design, with no, one, or two foliar application of 1 mM H2O2, on plants that were either continually watered or subjected to drought. The plants were tested both during the drought period and after they had resumed irrigation (recovered). Leaf water potential, chlorophyll a fluorescence, gas exchange, lipid peroxidation, H2O2 concentrations, phenols, proline, antioxidant enzyme activity, and sugar chemical profile were all measured. Our findings showed that H2O2 application generated metabolic alterations in tomato plants independent of water status, and that two applications in drought plants resulted in a 30% decrease in oxidative stress during drought and faster recovery following irrigation return, with greater production of defence-related molecules such as the APX enzyme, phenols, arabinose, and mannose. Continually watered plants also benefited from H2O2 application, which increased carbon assimilation by 35%. [ABSTRACT FROM AUTHOR]

When applied under abiotic stress conditions, triacontanol (TRIA) is effective in regulating the physicochemical processes in plants through mechanisms of defence such as abscisic acid (ABA) signalling. However, TRIA's role in relation to ABA and stomatal opening is unclear. Therefore, the objective of this study was to evaluate the effects of TRIA and ABA and their combinations on different variables related to stomatal regulation in Solanum lycopersicum, which is subjected to drought stress, and on the leaf epidermis. The negative effects of stress and responses triggered by ABA were reversed in plants treated with TRIA. TRIA increased stomatal conductance and photosynthetic activity in the early hours, and it was determined that TRIA produced larger stomata than did the other treatments. Moreover, the chloroplasts of plants treated with TRIA were significantly smaller and more numerous than those of the control, which could improve CO2 diffusion efficiency and may be related to the regulation of stomatal opening and photosynthesis. Finally, the abaxial epidermis tests reaffirmed the inhibitory effects of TRIA on ABA on stomatal opening. These results confirm the important role of TRIA in regulating various processes in plants and processes triggered by ABA, such as those related to stomatal regulation. [ABSTRACT FROM AUTHOR]

Yellow sticky traps (YSTs) are common tools for monitoring the greenhouse whitefly (GWF), Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), which can cause significant yield reduction in different greenhouse crops such as cucumber and tomato. In recent years, sticky traps equipped with green light-emitting diodes (LEDs) have also been (successfully) tested for catching GWFs. However, no study has observed GWF population dynamics at low population densities using such LED traps for early pest detection in crop stands. Therefore, a greenhouse experiment was conducted aiming to investigate the correlation between GWF populations on tomato crops (Solanum lycopersicum L. (Solanaceae)) and the numbers caught on yellow sticky traps and green LED traps, respectively. A small number of whiteflies was released into two pest-free greenhouse cabins, and populations on plants and traps were monitored for the duration of two months. The results show that the GWFs caught on LED traps correlate significantly positive with the population density on the tomato crops. Such a correlation was not found for standard YSTs. Moreover, the results indicate the possibility of early pest detection using LED traps. The findings are discussed in the context of the whiteflies' ecology and population dynamics in greenhouses. [ABSTRACT FROM AUTHOR]

Leveillula taurica has until recently been believed to be the causal pathogen of powdery mildew of tomatoes in Mauritius. However, in the year 2022, another powdery mildew species was detected on tomatoes under culture in various tomato growing localities of the island. Based on morphological comparison and molecular analysis, its identity was confirmed as Erysiphe neolycopersici (anam. Pseudoidium neolycopersici). This species has a worldwide distribution causing severe epidemics mainly on greenhouse tomatoes. There is evidence of the rapid spread of this pathogen during 2022–2023 causing serious infection of all tomato cultivars in greenhouse culture in Mauritius. The origin of these infections and its epidemiological consequences are discussed. [ABSTRACT FROM AUTHOR]

RNA interference (RNAi) is a regulatory and protective mechanism that plays a crucial role in the growth, development, and control of plant responses to pathogens and abiotic stresses. In spray-induced gene silencing (SIGS), exogenous double-stranded RNAs (dsRNA) are used to efficiently regulate target genes via plant surface treatment. In this study, we aimed to evaluate the effect of specific exogenous dsRNAs on silencing different regions (promoter, protein-coding and intron) of the target SlTRY tomato gene, encoding an R3-type MYB repressor of anthocyanin biosynthesis. We also assessed the impact of targeting different SlTRY regions on the expression of genes involved in anthocyanin and flavonoid biosynthesis. This study demonstrated the critical importance of selecting the appropriate gene target region for dsRNA action. The highest inhibition of the SlTRY gene expression and activation of anthocyanin biosynthesis was achieved by dsRNA complementary to the protein-coding region of SlTRY gene, compared with dsRNAs targeting the SlTRY promoter or intron regions. Silencing the SlTRY gene increased the content of anthocyanins and boosted levels of other substances in the phenylpropanoid pathway, such as caffeoyl putrescine, chlorogenic acid, ferulic acid glucoside, feruloyl quinic acid, and rutin. This study is the first to examine the effects of four different dsRNAs targeting various regions of the SlTRY gene, an important negative regulator of anthocyanin biosynthesis. [ABSTRACT FROM AUTHOR]

This study employed two prevalent plastic products - straws and microfiber as microplastics (MPs) to elucidate their largely unexplored effects on soil's properties and the growth of the tomato plant (Solanum lycopersicum L.). For this experiment, a completely randomized design (CRD) was adopted where, straw - polypropylene (PP), microfiber - polyester (PES) + polyamide (PA), and their combinations (PP + PES + PA) were mixed with soil using different concentrations – 0% (control), 0.4%, 1%, and 2% (treatments) and kept for 45 days at room temperature. The findings demonstrated that incorporating 2% mixed MPs in soil significantly decreased bulk density and electrical conductivity 7.29% and 67.3%, respectively, while soil pH increased 17.84% in cultures containing 1% microfiber. Maximum water holding capacity (MWHC), soil organic carbon (SOC), and soil organic matter (SOM) showed varied responses based on MPs type and concentration. Specifically, MWHC increased 16.4% with 2% microfiber but declined 13.3% with 0.4% straw. The highest decreased (30.65%) in SOC and SOM were evident in cultures with 1% microfiber whereas increased 9.68% and 8.33% in cultures with 0.4% straw. In terms of the growth traits of S. lycopersicum, substantial reductions in plant height (56.37%), leaf number (54.37%), and girth diameter (56.43%) were observed in 2% straw containing cultures. Although no plant mortality was noted, the most pronounced reductions in leaf area (62.44%) and total plant biomass (68.16%) occurred in 2% microfiber cultures. Therefore, the ramifications of these findings may contribute to a deeper comprehension of the mechanisms and effects of MPs on soil properties and above-ground plant growth. [ABSTRACT FROM AUTHOR]

Environmental conditions greatly influence the quality of tomato fruit by affecting the expression of genes, the abundance of metabolites, and the perception of sensorial attributes. In this study, a fruit transcriptome investigation, a sensory test, and a metabolomic analysis were performed to evaluate the impact of the environment on two popular tomato cultivars grown in two Italian regions. The transcriptional profile of each cultivar, cultivated in two different areas, highlighted differential expression in genes involved in pathways related to cell wall components such as pectin, lignin, and hemicellulose and sugars as well as in amino acids, phenylpropanoids, and pigment synthesis. The cultivation area mainly affects sensory attributes related to texture and flavor and the metabolic pattern of cell wall precursors, sugars, glutamate, aspartate, and carotenoids. In the two genotypes cultivated in the same environment, some attributes and fruit-related quality processes are similarly affected, while others are differently influenced based on the specific genetic makeup of the tomato. A combination of transcriptomic, sensory, and metabolomic data obtained from the two tomato genotypes revealed that the environment has a profound effect on specific sensory traits, providing information on factors that shape the specific characteristics and genetic targets for improving tomato fruit characteristics. [ABSTRACT FROM AUTHOR]

The use of agricultural waste is becoming more common with the spread of awareness of sustainable life. In the present study, different concentrations (10 gr/L, 15 gr/L, 20 gr/L) of aqueous extracts were obtained from tomato (Solanum lycopersicum) leaves as agricultural waste and fabrics containing 100% wool were coloured with these extracts by using infra-red dyeing machine. Aluminium, iron and copper based mordants, which are frequently used in natural dyeing, were added to the extracts. After dyeing process, colours in alluring brown, green and yellow tones were obtained in the fabrics. According to the spectrophotometer measurements, colour yield (K/S) of the samples increased proportionally with increasing concentrations. Washing and rubbing fastness of the dyed wool samples were good, except for the samples dyed with iron-based mordant added extract. [ABSTRACT FROM AUTHOR]

The causal agent of tomato leaf mold, Cladosporium fulvum, is prevalent in greenhouses worldwide, especially under high humidity conditions. Despite its economic impact, studies on antifungal agents targeting C. fulvum remain limited. This study evaluates biocontrol agents (BCAs) as alternatives to chemical controls for managing this disease, alongside the strobilurin fungicide azoxystrobin. From a Moroccan collection of potential BCAs, five bacterial isolates (Alcaligenes faecalis ACBC1, Pantoea agglomerans ACBC2, ACBP1, ACBP2, and Bacillus amyloliquefaciens SF14) and three fungal isolates (Trichoderma spp. OT1, AT2, and BT3) were selected and tested. The in vitro results demonstrated that P. agglomerans isolates reduced mycelial growth by over 60% at 12 days post-inoculation (dpi), while Trichoderma isolates achieved 100% inhibition in just 5 dpi. All bacterial isolates produced volatile organic compounds (VOCs) with mycelial inhibition rates ranging from 38.8% to 57.4%. Likewise, bacterial cell-free filtrates significantly inhibited the pathogen's mycelial growth. Greenhouse tests validated these findings, showing that all the tested isolates were effective in reducing disease incidence and severity. Azoxystrobin effectively impeded C. fulvum growth, particularly in protective treatments. Fourier transform infrared spectroscopy (FTIR) analysis revealed significant biochemical changes in the treated plants, indicating fungal activity. This study provides valuable insights into the efficacy of these BCAs and azoxystrobin, contributing to integrated management strategies for tomato leaf mold disease. [ABSTRACT FROM AUTHOR]

Tomato Solanum lycopersicum is an important economic fruit, and widely consumed for its high nutritional quality. Our previous study found that AtERF022, a member of Arabidopsisthaliana ethylene response factors (ERFs) group III, acted a vital role in Arabidopsis growth and development. However, whether or how endogenous AtERF022 confers tomato fruit quality is still elusive. To explore the role of AtERF022 gene in tomato fruit ripening and nutritional quality, we generated AtERF022-overexpressing tomato line by transgenic and plant tissue culture technology. Our results showed that the higher expression of AtERF022 was found in tomato flowers and fruits, especially in orange ripening stage of fruits. Compared to wild-type, AtERF022-overexpressing tomato exhibited morphological growth advantages and elevated fruit ripening and nutritional quality. Further experiments and transcriptome sequencing showed that overexpression of AtERF022 enhanced the expression of genes involved in ethylene biosynthesis, cell wall metabolism, chlorophyll degradation, carotenoids and flavonoids biosynthesis, and thereby promoting fruit ripening, β-carotene, flavonoids, vitamin C and total phenols accumulation. Together, our results provide genetic evidence that AtERF022 regulates tomato fruit ripening and nutritional quality. [ABSTRACT FROM AUTHOR]

Summary: Plant secreted peptides RAPID ALKALINISATION FACTORs (RALFs), which act through the receptor FERONIA (FER), play important roles in plant growth. However, it remains unclear whether and how RALF‐FER contributes to the trade‐off of plant growth–defense.Here, we used a variety of techniques such as CRISPR/Cas9, protein–protein interaction and transcriptional regulation methods to investigate the role of RALF2 and its receptor FER in regulating lignin deposition, root growth, and defense against Fusarium oxysporum f. sp. lycopersici (Fol) in tomato (Solanum lycopersicum).The ralf2 and fer mutants show reduced primary root length, elevated lignin accumulation, and enhanced resistance against Fol than the wild‐type. FER interacts with and phosphorylates MYB63 to promote its degradation. MYB63 serves as an activator of lignin deposition by regulating the transcription of dirigent protein gene DIR19. Mutation of DIR19 suppresses lignin accumulation, and reverses the short root phenotype and Fol resistance in ralf2 or fer mutant.Collectively, our results demonstrate that the RALF2‐FER‐MYB63 module fine‐tunes root growth and resistance against Fol through regulating the deposition of lignin in tomato roots. The study sheds new light on how plants maintain the growth–defense balance via RALF‐FER. [ABSTRACT FROM AUTHOR]

Biostimulants such as seaweed extracts are widely used to stimulate plant growth and crop productivity under optimal or stressful conditions, constituting a sustainable strategy to mitigate the impacts of abiotic stress on plant performance. In this study, a growth experiment was conducted to evaluate the effects of an aqueous extract from the seaweed Padina gymnospora on the physiological, biochemical, and molecular characteristics of Solanum lycopersicum under salt stress. The experiment included four treatments: 1) control plants, 2) plants irrigated with 300 mM NaCl solution, 3) plants treated with the P. gymnospora extract, and 4) plants treated with the P. gymnospora extract and irrigated with 300 mM NaCl solution. Salt stress increased the activity of antioxidant enzymes (catalase and superoxide dismutase) and resulted in the overaccumulation of the osmolyte proline and flavonoids while enhancing photosynthetic performance and chlorophyll content. In addition, treatment with P. gymnospora extract increased total reducing sugars and phenols in salt-stressed plants, which was correlated with DPPH and ABTS antioxidant activity. The induction of stress-responsive genes, such as SlHB7, SlSOD1, SlRD29, and SlHKT, appears to be a major factor modulating the responses to P. gymnospora extract application in tomato plants. The results of this study demonstrate that the application of P. gymnospora to tomato plants attenuated the damage caused by salt stress. It is essential to continue studying the potential of seaweed extracts to mitigate stress in plants, given the promising agricultural applications of these novel biostimulants. [ABSTRACT FROM AUTHOR]

In Honduras, tomato (Solanum lycopersicum L.) is an economically important crop for farmers because of its high domestic consumption, year-round production, and high export potential. However, tomato production faces challenges such as diseases and pests and is confounded by climate change, all of which reduce productivity and quality. Evaluating the adaptation of tomato cultivars is critical to ensuring the long-term sustainability and resilience of the horticulture sector in the region. The objective of this study was to identify tomato lines with adaptability, high yield, pest, and disease resistance under greenhouse and open field production conditions for the Honduran market. Ten tomato lines and two commercial hybrids were evaluated between Feb and Jul 2022 in San Antonio de Oriente, Francisco Morazan, Honduras. Desirable traits related to vegetative growth, productivity, fruit quality, and resistance to insect pests and diseases were measured. Seven lines were highly adapted and had high vegetative growth. The tomato lines were not significantly different in terms of tomato yellow leaf curl disease and late blight disease index; however, the fruit borer susceptibility varied, with AVTO1908 being the most susceptible. The highest performing line was AVTO1903, which had the greatest total marketable yield in both the open field (101.3 t·ha-1) and greenhouse (62.1 t·ha-1). Additionally, AVTO1903 and AVTO1915 had good quality traits (roundness index, total soluble solids, and dry matter), thus demonstrating their potential for sustainable and high-yielding cultivation in Honduras. The growth and productivity of the tomato lines were highly influenced by the environment. This work highlights the advantages of introducing exotic cultivars to combat the effects of climate change and ensure sustained production; however, further research is needed to ensure that local farmer and consumer demands are met. [ABSTRACT FROM AUTHOR]

Background: Phosphorus (P) is one of the nonrenewable resources of critical importance in agricultural production. P is present in soil in organic and inorganic forms. Phytate constitutes the majority of organic P in soil. Phytate binds strongly to the solid phase of the soil and becomes unavailable for use by plants. Therefore, the soluble phytate‐P ratio in soil is mostly at very low levels. Plants and associated microorganisms secrete organic acids and hydrolyzing enzymes such as phytase to dissolve phytate in the soil. Both the solubility of phytate and phytase activity are limiting properties for the uptake of phytate‐P by plants. Aims: Our aim was to evaluate the effects of phytase immobilized on zinc oxide nanoparticles (ZnO Np) on tomato plant (Solanum lycopersicum) growth parameters. In this study, seedling period was analyzed. Methods: In the study, phytase activity of 13 different bacteria was investigated, and phytase was purified from Lactobacillus kefiri, showing the highest activity, and its biochemical properties were determined. Phytase was immobilized on zinc oxide (ZnO) nanoparticles and characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopes analysis. The effects of ZnONps, immobilized phytase, and free phytase on the growth parameters of tomato plant were investigated. Tomato seeds were soaked with ZnONps, immobilized and free phytase for 30 min at room temperature and sown in pots containing suitable growing medium. Vegetative development of tomato plant, plant height, number of lateral branches, main stem diameter, distance between nodes, number of nodes, main root, and shoot length were determined. Results: Phytase was partially purified with 7.60% recovery and specific activity of 1758.5 (EU mg−1 protein). Molecular mass of partially purified phytase was approx.72 kD, optimum pH and temperature values were determined as pH 5.0 and 70–80°C, respectively. Immobilized phytase caused a significant increase of 41.1% in plant height, 64.1% in main root, and 36.1% in shoot length in tomato plants compared to the control. In addition, a significant increase was observed in the number of side branches, main stem diameter, distance between nodes, number of nodes, and vegetative growth of the plant. Conclusions: The results showed that the immobilized phytase enzyme has a positive effect on seedling growth in tomato and can be used in tomato cultivation in the future. [ABSTRACT FROM AUTHOR]

The tomato (Solanum lycopersicum L.), a widely cultivated and economically important vegetable crop, is subject to a number of biotic and abiotic stresses in nature. Several abiotic and biotic stresses have been demonstrated to elevate the concentration of cytosolic free Ca2+ ([Ca2+]i) in Arabidopsis due to the influx of calcium ions. In this study, recombinant aequorin was introduced into the tomato in order to investigate the change in [Ca2+]i when treated with exogenous Ca2+. This resulted in strong luminescence signals, which were mainly observed in the roots. Luminescence signals were also detected in the whole plant, including the leaves, when a surfactant (Silwet L-77) was added to coelenterazine. The concentration of [Ca2+]i increased with the dosage of NaCl/elf18. The luminescence signals also showed a lower increase in intensity with elf18 treatment compared to NaCl treatment. Furthermore, the [Ca2+]i responses to other abiotic or biotic stresses, such as H2O2 and Pep1, were also evaluated. It was found that this transgenic tomato expressing aequorin can effectively detect changes in [Ca2+]i levels. The transgenic tomato expressing aequorin represents an effective tool for detecting changes in [Ca2+]i and provides a solid basis for investigating the adaptation mechanisms of tomatoes to various abiotic and biotic stresses. Moreover, the aequorin-based system would be a highly valuable tool for studying the specificity and crosstalk of plant signalling networks under abiotic and biotic stresses in tomatoes. [ABSTRACT FROM AUTHOR]

Compost residue enriches soil health with the potential to enhance plant metabolism and hormonal balance, but has not yet been studied. A study was performed to determine how prevailing compost residue induces tomato (Solanum lycopersicum 'Scotia') plant morpho-physiology, phytohormones, and secondary metabolites. Plants were grown in soils with a previous history of annual (AN) and biennial (BI) compost amendments. The controls were soil without compost (C) amendment and municipal solid waste compost (MSWC) alone. The MSWC- and AN-plants had similar and significantly (p < 0.05) highest growth and photosynthetic activities compared to the BI- or C-plants. Total phenolics and lipid peroxidase activity were significantly (p < 0.001) high in BI-plants, while hydrogen peroxide and antioxidant capacity were significantly (p < 0.001) high in AN-plants. MSWC-plants recorded the highest cis-abscisic acid, followed by AN-, and then BI- and C-plants. Cis-zeatin, trans-zeatin, and isopentenyladenine ribosides were detected in the MSWC- and AN-plants but not in the BI- or C-plants. Furthermore, gibberellins GA53, GA19, and GA8 were high in the MSWC-plants, but only GA8 was detected in the AN plants and none in the others. Besides, MSWC plants exhibited the highest content of 1-aminocyclopropane-1-carboxylic acid. Conjugated salicylic acid was highest in the BI-plants, while jasmonic acid-isoleucine was highest in MSWC-plants and C plants. In conclusion, prevailing compost chemical residues upregulate plant growth, phytohormones, and metabolic compounds that can potentially increase plant growth and abiotic stress defense. Future work should investigate the flow of these compounds in plants under abiotic stress. [ABSTRACT FROM AUTHOR]

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Phenylpropanoids, a class of specialized metabolites, play crucial roles in plant growth and stress adaptation and include diverse phenolic compounds such as flavonoids. Phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS) are essential enzymes functioning at the entry points of general phenylpropanoid biosynthesis and flavonoid biosynthesis, respectively. In Arabidopsis, PAL and CHS are turned over through ubiquitination-dependent proteasomal degradation. Specific kelch domain-containing F-Box (KFB) proteins as components of ubiquitin E3 ligase directly interact with PAL or CHS, leading to polyubiquitinated PAL and CHS, which in turn influences phenylpropanoid and flavonoid production. Although phenylpropanoids are vital for tomato nutritional value and stress responses, the post-translational regulation of PAL and CHS in tomato remains unknown. We identified 31 putative KFB-encoding genes in the tomato genome. Our homology analysis and phylogenetic study predicted four PAL-interacting SlKFBs, while SlKFB18 was identified as the sole candidate for the CHS-interacting KFB. Consistent with their homolog function, the predicted four PAL-interacting SlKFBs function in PAL degradation. Surprisingly, SlKFB18 did not interact with tomato CHS and the overexpression or knocking out of SlKFB18 did not affect phenylpropanoid contents in tomato transgenic lines, suggesting its irreverence with flavonoid metabolism. Our study successfully discovered the post-translational regulatory machinery of PALs in tomato while highlighting the limitation of relying solely on a homology-based approach to predict interacting partners of F-box proteins.Key message: Despite its highest sequence homology with Arabidopsis CHS-interacting KFB among 31 tomato KFBs, SlKFB18 does not function in CHS degradation, while predicted PAL-interacting SlKFBs function in PAL degradation in tomato. [ABSTRACT FROM AUTHOR]

The use of natural-origin biomaterials in bioengineering has led to innovative approaches in agroforestry. Bacterial cellulose (BC), sharing the same chemical formula as plant-origin cellulose (PC), exhibits significantly different biochemical properties, including a high degree of crystallinity and superior water retention capacity. Previous research showed that natural-origin glucose-based chitin enhanced plant growth in both herbaceous and non-herbaceous plants. In this study, we produced BC in the laboratory and investigated its effects on the substrate and on Solanum lycopersicum seedlings. Soil amended with BC increased root growth compared with untreated seedlings. Additionally, under limited irrigation conditions, BC increased global developmental parameters including fresh and dry weight, as well as total carbon and nitrogen content. Under non-irrigation conditions, BC contributed substantially to plant survival. RNA sequencing (Illumina®) on BC-treated seedlings revealed that BC, despite its bacterial origin, did not stress the plants, confirming its innocuous nature, and it lightly induced genes related to root development and cell division as well as inhibition of stress responses and defense. The presence of BC in the organic substrate increased soil availability of phosphorus (P), iron (Fe), and potassium (K), correlating with enhanced nutrient uptake in plants. Our results demonstrate the potential of BC for improving soil nutrient availability and plant tolerance to low irrigation, making it valuable for agricultural and forestry purposes in the context of global warming. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate phenotypic traits and genetic diversity of the 13 tomato (Solanum lycopersicum L.) varieties and 6 hybrids developed at the Institute of Horticulture Lithuanian Research Centre for Agriculture and Forestry (LRCAF IH). For the molecular characterisation, seven previously published microsatellite markers (SSR) were used. A24 and 26 alleles were detected in tomato varieties and hybrids, respectively. Based on the polymorphism information content (PIC) value, the most informative SSR primers for varieties were TMS52, TGS0007, LEMDDNa and Tom236-237, and the most informative SSR primers for hybrids were SSR248 and TMS52. In UPGMA cluster analysis, tomato varieties are grouped in some cases due to genetic relationships, as the same cluster cultivars 'Viltis' (the parent of cv. 'Laukiai') and 'Aušriai' (the progeny of cv. 'Jurgiai') are present. The grouping of all hybrids in the dendrogram is related to the parental forms, and it shows the usefulness of molecular markers for tomato breeding, as they can be used to trace the origin of hybrids and, eventually, varieties accurately. The knowledge about the genetic background of Lithuanian tomato cultivars will help plan targeted crosses in tomato breeding programs. [ABSTRACT FROM AUTHOR]

Climate change is one of the biggest challenges to the world at present. Tomato is also suffered from devastating yield loss due to climate change. The domesticated tomato (Solanum lycopersicum) is presumed to be originated from the wild tomato (S. pimpinellifolium). In this study, we compared the climate data of S. pimpinellifollium with the domesticated tomato, predicted the suitable regions of S. pimpinellifollium in China using MaxEnt model and assessed their tolerance to drought stress. We found that the predicted suitable regions of wild tomato are highly consistent with the current cultivated regions of domesticated tomato, suggesting that the habitat demand of domesticated tomato descended largely from its ancestor, hence the habitat information of wild tomato could provide a reference for tomato cultivation. We further predicted suitable regions of wild tomato in the future in China. Finally, we found that while average drought tolerance between wild and domesticated tomato accessions shows no difference, tolerance levels among wild tomato accessions exhibit higher variation, which could be used for future breeding to improve drought resistance. To summarize, our study shows that suitable regions of wild tomato provide insights into domesticated tomato cultivation in China. [ABSTRACT FROM AUTHOR]

Implementing sustainable crop protection practices is crucial to protect global harvests and ensure high-quality food supplies. While priming is an established method in seed production for the fortification of plants against various stresses, it is not yet a standard practice in transplant cultivation. Thus, we evaluated the long-term effects of thermopriming—a heat-based priming technique—on the growth, development, and fruit yield of tomato plants. Following a recovery period of about six weeks for thermoprimed plants without stress inducers, we subjected them to subsequent salt stress to ascertain the persistence of the priming effects. Additionally, we compared the efficacy of thermopriming with benzothiadiazole (BTH), a chemical elicitor, in enhancing plant resilience to abiotic stress. While BTH application negatively impacted both plant growth and fruit health, thermopriming showed no such adverse effects on these parameters. Instead, thermopriming initially enhanced the plant defense mechanisms by increasing the accumulation of protective phenols and flavonoids in the leaves. Interestingly, while thermopriming did not alter the response to salt stress, it notably strengthened the overall resilience of the plants. Our findings underscore both the potential and temporal constraints of thermopriming memory. Nonetheless, primed plants exhibited temporarily increased stress tolerance, offering a means to safeguard the offspring. [ABSTRACT FROM AUTHOR]

SUMMARY: Polyamines are involved in several plant physiological processes. In Arabidopsis thaliana, five FAD‐dependent polyamine oxidases (AtPAO1 to AtPAO5) contribute to polyamine homeostasis. AtPAO5 catalyzes the back‐conversion of thermospermine (T‐Spm) to spermidine and plays a role in plant development, xylem differentiation, and abiotic stress tolerance. In the present study, to verify whether T‐Spm metabolism can be exploited as a new route to improve stress tolerance in crops and to investigate the underlying mechanisms, tomato (Solanum lycopersicum) AtPAO5 homologs were identified (SlPAO2, SlPAO3, and SlPAO4) and CRISPR/Cas9‐mediated loss‐of‐function slpao3 mutants were obtained. Morphological, molecular, and physiological analyses showed that slpao3 mutants display increased T‐Spm levels and exhibit changes in growth parameters, number and size of xylem elements, and expression levels of auxin‐ and gibberellin‐related genes compared to wild‐type plants. The slpao3 mutants are also characterized by improved tolerance to drought stress, which can be attributed to a diminished xylem hydraulic conductivity that limits water loss, as well as to a reduced vulnerability to embolism. Altogether, this study evidences conservation, though with some significant variations, of the T‐Spm‐mediated regulatory mechanisms controlling plant growth and differentiation across different plant species and highlights the T‐Spm role in improving stress tolerance while not constraining growth. [ABSTRACT FROM AUTHOR]

Considering the stricter European regulations for chemical pesticides (e.g. abolishment of the use of chemical soil fumigation products, such as methyl bromide), the need for more sustainable plant protection products is strongly increasing. In this research, Product X, an innovative mixture of bio-nematicidal compounds was developed and evaluated for efficacy. Product X showed a direct nematicidal effect against the root-knot nematode Meloidogyne incognita. In pot trials with tomato plants infected with M. incognita, Product X treatment lead to a significant reduction in nematode-induced gall formation. mRNA-sequencing indicated alterations in phytohormone levels and ROSmetabolism in tomato roots upon treatment with Product X, which was subsequently biochemically validated. Increased levels of abscisic acid and peroxidase activity seem to be the main factors in the response of tomato plants to Product X. Long-term administration of Product X did not yield negative effects on tomato growth or yield. In conclusion, Product X provides a new interesting mix of bio-active compounds in the combat against rootknot nematodes. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L.) plants, wild type Ailsa Craig, and carotenoid mutant tangerine that accumulates prolycopene instead of all-trans-lycopene were exposed to a combined treatment by low light and low temperature for 5 days. The ability of plants to recover from the stress after development for 3 days at control conditions was followed as well. The suffered oxidative stress was evaluated by the extent of pigment content, lipid peroxidation, membrane stability, and H2O2 generation. The level of MDA content under combined treatment in tangerine implies that the mutant demonstrates lower sensitivity to stress in comparison with Ailsa Craig. The oxidative protective strategy of plants was estimated by following the antioxidant and antiradical activity of phenolic metabolites, including anthocyanins, as well as the activities of antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT). Presented results revealed that the oxidative stress was much stronger expressed after exposure of both types of plants to low light combined with low temperature compared to that after treatment with only low light. The most significant antioxidant protection was provided by phenolic substances, including anthocyanins. The lower sensitivity of tangerine plants to low light can be attributed to the higher activity of the antioxidant enzyme CAT. [ABSTRACT FROM AUTHOR]

In recent years, the exploration of genome three-dimensional (3D) conformation has yielded profound insights into the regulation of gene expression and cellular functions in both animals and plants. While animals exhibit a characteristic genome topology defined by topologically associating domains (TADs), plants display similar features with a more diverse conformation across species. Employing advanced high-throughput sequencing and microscopy techniques, we investigated the landscape of 26 histone modifications and RNA polymerase II distribution in tomato (Solanum lycopersicum). Our study unveiled a rich and nuanced epigenetic landscape, shedding light on distinct chromatin states associated with heterochromatin formation and gene silencing. Moreover, we elucidated the intricate interplay between these chromatin states and the overall topology of the genome. Employing a genetic approach, we delved into the role of the histone modification H3K9ac in genome topology. Notably, our investigation revealed that the ectopic deposition of this chromatin mark triggered a reorganization of the 3D chromatin structure, defining different TAD-like borders. Our work emphasizes the critical role of H3K9ac in shaping the topology of the tomato genome, providing valuable insights into the epigenetic landscape of this agriculturally significant crop species. [ABSTRACT FROM AUTHOR]

During the survey of open tomato fields in Vojvodina (Serbia), characteristic anthracnose disease symptoms, including black, circular, sunken, and watery lesions, were observed in about 20% of fruits in September 2018. Subsequent pathogen isolations formed white aerial mycelia and numerous spherical, black conidiomata on the Potato Dextrose Agar. Ten representative isolates produced hyaline, smooth-walled, cylindrical, and aseptate conidia. The presence of initially brownish necrotic lesions on the tomato, which later expanded into large rotted areas, ultimately leading to complete fruit rot, confirmed the pathogenicity of the tested isolates. Molecular identification was performed using Bayesian analysis of concatenated ITS, TUB2, CHS-1, and ACT loci. Based on the combination of the morphological and molecular features, the fungus Colletotrichum nigrum was identified as the causal pathogen. As this is the first report on this fungal pathogen on tomatoes in Serbia, it highlights the importance of early and accurate detection for effective disease prevention, thus reducing crop damage and market losses. [ABSTRACT FROM AUTHOR]

Among the many biotic factors with adverse effects on Solanum lycopersicum (tomato), diseases caused by fungi, viruses and nematodes are notable. Since the genome of S. lycopersicum became available, efforts have continued to identify the genes and proteins associated with the plant defence activity. One such gene family belongs to TIR-NBS- -LRR (TNL), a subfamily of larger NBS-LRR genes. In total, 27 full-length TNLs were identified via genome wide analysis. Four pairs of segmental duplication events were observed involving different pairs of chromosomes, except the pairing of Solyc02g082050-Solyc02g032650, which were both present on chromosome 2. More than twenty nine percent (29.63%) of the genes were localised on chromosome 1 alone. Hormone-mediated biotic stress-responsive cis-regulatory elements were detected for methyl-jasmonate, salicylic acid (TCA motif) and ethylene (ERE motif). Differential gene expression was observed for many genes under different plant tissues and biotic stresses. The upregulation of many genes including SlBS4 was observed against Alternaria solani attacks in the disease tolerant varieties. Altogether, the results suggested that TNLs play a significant role in plant defence under biotic stress. [ABSTRACT FROM AUTHOR]

[Objective] Fatty acid desaturase（FAD）is a key enzyme that catalyzes the synthesis of unsaturated fatty acids in plants, and it plays an important role in plant growth and development and response to adversity stress. This work aims to identify the tomato（Solanum lycopersi）SlFAD gene family and provide a theoretical basis for the study of tomato SlFAD gene family function and genetic improvement. [Method] Bioinformatics was used to identify the members of its gene family, and to study its physical and chemical properties, gene structure, phylogenetic tree and expression patterns. [Result] The total of 26 SlFAD genes were identified in the tomato genome, which can be divided into 4 sub-families. The analysis of physical and chemical properties showed that the number of amino acids of SlFAD protein was 119-912, the molecular weight was 13 288.27-102 522.25 Da. The SlFAD protein mainly existed in the nature of alkaline protein, and most of the members of the SlFAD family were stable proteins and hydrophilic proteins. Subcellular localization predicted that the members of the SlFAD gene family mainly were located in the endoplasmic reticulum. Genetic feature analysis showed that the members of the same subfamily hadsimilar genetic structure and conservative sequence. The analysis of cis-acting elements in the promotor showed that the largest number of components was related to light response and hormone response. Chromosome positioning revealed that 26 members of the SlFAD family were distributed on 10 chromosomes, and the largest number of members on chromosome 6 and 12. Secondary structure prediction demonstrated that 26 members of the SlFADs family were alpha-spiral and β-turning angle were the main ones. Transcriptome data and RT-qPCR analysis showed that the SlFAD1, SlFAD4 and SlFAD18 genes were highly expressed in mature anthers, and SlFAD23 was highly expressed in the root tip, indicating SlFAD1, SlFAD4 and SlFAD18 participated in the anther development, SlFAD23 participated in the root tip development. Under low-temperature stress, the expressions of SlFAD6 and SlFAD21 were inhibited, indicating that SlFAD6 and SlFAD21 might be related to low-temperature response, SlFAD1 and SlFAD14 at the beginning of low-temperature stress. The period significantly increased and then inhibited, indicating that the gene played an important role in the early stage of low-temperature stress. [Conclusion] The SlFAD gene family plays an important role in the growth and development of tomato roots, leaves, anthers and low-temperature stress [ABSTRACT FROM AUTHOR]

Key message: Whole-genome QTL mining and meta-analysis in tomato for resistance to bacterial and fungal diseases identified 73 meta-QTL regions with significantly refined/reduced confidence intervals. Tomato production is affected by a range of biotic stressors, causing yield losses and quality reductions. While sources of genetic resistance to many tomato diseases have been identified and characterized, stability of the resistance genes or quantitative trait loci (QTLs) across the resources has not been determined. Here, we examined 491 QTLs previously reported for resistance to tomato diseases in 40 independent studies and 54 unique mapping populations. We identified 29 meta-QTLs (MQTLs) for resistance to bacterial pathogens and 44 MQTLs for resistance to fungal pathogens, and were able to reduce the average confidence interval (CI) of the QTLs by 4.1-fold and 6.7-fold, respectively, compared to the average CI of the original QTLs. The corresponding physical length of the CIs of MQTLs ranged from 56 kb to 6.37 Mb, with a median of 921 kb, of which 27% had a CI lower than 500 kb and 53% had a CI lower than 1 Mb. Comparison of defense responses between tomato and Arabidopsis highlighted 73 orthologous genes in the MQTL regions, which were putatively determined to be involved in defense against bacterial and fungal diseases. Intriguingly, multiple genes were identified in some MQTL regions that are implicated in plant defense responses, including PR-P2, NDR1, PDF1.2, Pip1, SNI1, PTI5, NSL1, DND1, CAD1, SlACO, DAD1, SlPAL, Ph-3, EDS5/SID1, CHI-B/PR-3, Ph-5, ETR1, WRKY29, and WRKY25. Further, we identified a number of candidate resistance genes in the MQTL regions that can be useful for both marker/gene-assisted breeding as well as cloning and genetic transformation. [ABSTRACT FROM AUTHOR]

Root‐knot nematodes (RKNs) are microscopic parasitic worms able to infest the roots of thousands of plant species, causing massive crop yield losses worldwide. They evade the plant's immune system and manipulate plant cell physiology and metabolism to transform a few root cells into giant cells, which serve as feeding sites for the nematode. RKN parasitism is facilitated by the secretion in planta of effector molecules, mostly proteins that hijack host cellular processes. We describe here a conserved RKN‐specific effector, effector 12 (EFF12), that is synthesized exclusively in the oesophageal glands of the nematode, and we demonstrate its function in parasitism. In the plant, MiEFF12 localizes to the endoplasmic reticulum (ER). A combination of RNA‐sequencing analysis and immunity‐suppression bioassays revealed the contribution of MiEFF12 to the modulation of host immunity. Yeast two‐hybrid, split luciferase and co‐immunoprecipitation approaches identified an essential component of the ER quality control system, the Solanum lycopersicum plant bap‐like (PBL), and basic leucine zipper 60 (BZIP60) proteins as host targets of MiEFF12. Finally, silencing the PBL genes in Nicotiana benthamiana decreased susceptibility to Meloidogyne incognita infection. Our results suggest that EFF12 manipulates PBL function to modify plant immune responses to allow parasitism. [ABSTRACT FROM AUTHOR]

Plant viral diseases compromise the growth and yield of the crop globally, and they tend to be more serious under extreme temperatures and drought climate changes. Currently, regulatory dynamics during plant development and in response to virus infection at the plant cell level remain largely unknown. In this study, single‐cell RNA sequencing on 23 226 individual cells from healthy and tomato chlorosis virus‐infected leaves was established. The specific expression and epigenetic landscape of each cell type during the viral infection stage were depicted. Notably, the mesophyll cells showed a rapid function transition in virus‐infected leaves, which is consistent with the pathological changes such as thinner leaves and decreased chloroplast lamella in virus‐infected samples. Interestingly, the F‐box protein SKIP2 was identified to play a pivotal role in chlorophyll maintenance during virus infection in tomato plants. Knockout of the SlSKIP2 showed a greener leaf state before and after virus infection. Moreover, we further demonstrated that SlSKIP2 was located in the cytomembrane and nucleus and directly regulated by ERF4. In conclusion, with detailed insights into the plant responses to viral infections at the cellular level, our study provides a genetic framework and gene reference in plant–virus interaction and breeding in the future research. Summary statement: The responses of different cell types in tomato leaves to tomato chlorosis virus (ToCV) infection were analyzed at the cellular level. We further determined that ERF4 regulates SlSKIP2, and the latter plays a crucial role in chlorophyll maintenance during ToCV infection in tomato leaves. [ABSTRACT FROM AUTHOR]

Grafting facilitates the management of phytodiseases, especially of soils, but the growth and development of the grafted plant depend on the compatibility with rootstocks. The objective was to evaluate the graft union and survival, the growth characteristics, fruit biometrics, yield and physiological characteristics of the tomato plant 'Santa Clara' on five rootstocks. The study was conducted at the Pici Campus of the Federal University of Ceará in Fortaleza, Ceará state, Brazil. The seven treatments were tomato 'Santa Clara' ungrafted and self‐grafted, or grafted onto cherry tomato 'Vermelho', hybrid tomato 'Guardiao', eggplant 'Comprida Roxa', jiló 'Comprido Grande Rio' (Solanum gilo) and cocona (Solanum sessiliflorum). Cleft grafting was used. The growth characteristics evaluated were stem diameter (SD), plant height (PH), and number of commercial (NCF) and total (NTF) fruits. The biometric characteristics of the fruits (diameter‐FD, length‐FL and average mass‐AMF) and productive (commercial‐CFM and total‐TFM fruit mass) and yield of commercial (YCF) and total (YTF) fruits were estimated per hectare. Physiological evaluations were performed to obtain the internal concentration of CO2 (Ci), transpiration rate (E), stomatal conductance (Gs), liquid photosynthesis (A), ratio between internal CO2 and the environment (Ci/Ca) and carboxylation efficiency (A/Ci). The graft union and survival of S. lycopersicum plants was 100% at 10 days after grafting. The number of commercial and total fruits were higher in non‐grafted tomato plants. The FD of the plants was higher with rootstocks of the 'Vermelho' cherry tomato and 'Guardião' hybrid, the CFM and TFM with ungrafted, the AMF and TFM with 'Vermelho' cherry tomato and the YCF and YTF with ungrafted and grafting on the 'Vermelho' cherry tomato. The tomato plant 'Santa Clara' completed its development in rootstocks and, therefore, they are compatible with this plant. The production of tomato fruits was higher with grafting on the 'Vermelho' cherry tomato with diameter and productivity similar to those of the ungrafted plants, indicating that this tomato cultivar can be used as rootstock. [ABSTRACT FROM AUTHOR]

We evaluated the allelopathic potential of Ageratum conyzoides L. aqueous leaf extracts on germination and growth of Solanum lycopersicum L. (tomato), Zea mays L. (corn) and Lactuca sativa L. (lettuce). Total phenolic content (TPC) of the soil rhizosphere was determined by spectrophotometry method. We also investigated the habitat attributes (e.g., canopy openness and leaf area index (LAI)) of A. conyzoides infested region. Results revealed that aqueous leaf extracts had both inhibitory and stimulatory effects on the germination, plumule length and radicle length of crops. All extract concentrations inhibited the germination of Z. mays and L. sativa seeds, but no effects on S. lycopersicum, except at 50 gL-1. Conversely, plumule and radicle lengths were stimulated in S. lycopersicum and L. sativa for majority of extract concentrations but they were inhibited in Z. mays. The inhibitory allelopathic effects of A. conyzoides were maximum in Z. mays (i.e., S. lycopersicum < L. sativa < Z. mays). TPC values in invaded soil were 0.046 g/L and 0.48 g/L with gallic acid and catechol, respectively. This study showed that the presence of allelochemicals in A. conyzoides invaded soil, which potentially influenced the crops, thereby validating the 'novel weapon (NW) hypothesis'. The recorded values of habitat attributes were associated with the successful spread of A. conyzoides and hence, its allelopathic effects on test crops. [ABSTRACT FROM AUTHOR]

JOINTLESS (J) was isolated in tomato (Solanum lycopersicum) from mutants lacking a flower pedicel abscission zone (AZ) and encodes a MADS-box protein of the SHORT VEGETATIVE PHASE/AGAMOUS-LIKE 24 subfamily. The loss of J function also causes the return to leaf initiation in the inflorescences, indicating a pivotal role in inflorescence meristem identity. Here, we compared jointless (j) mutants in different accessions that exhibit either an indeterminate shoot growth, producing regular sympodial segments, or a determinate shoot growth, due to the reduction of sympodial segments and causal mutation of the SELF-PRUNING (SP) gene. We observed that the inflorescence phenotype of j mutants is stronger in indeterminate (SP) accessions such as Ailsa Craig (AC), than in determinate (sp) ones, such as Heinz (Hz). Moreover, RNA-seq analysis revealed that the return to vegetative fate in j mutants is accompanied by expression of SP , which supports conversion of the inflorescence meristem to sympodial shoot meristem in j inflorescences. Other markers of vegetative meristems such as APETALA2c and branching genes such as BRANCHED 1 (BRC1a/b) were differentially expressed in the inflorescences of j (AC) mutant. We also found in the indeterminate AC accession that J represses homeotic genes of B- and C-classes and that its overexpression causes an oversized leafy calyx phenotype and has a dominant negative effect on AZ formation. A model is therefore proposed where J , by repressing shoot fate and influencing reproductive organ formation, acts as a key determinant of inflorescence meristems. [ABSTRACT FROM AUTHOR]

Establishment of arbuscular mycorrhiza relies on a plant signaling pathway that can be activated by fungal chitinic signals such as short-chain chitooligosaccharides and lipo-chitooligosaccharides (LCOs). The tomato LysM receptor-like kinase SlLYK10 has high affinity for LCOs and is involved in root colonization by arbuscular mycorrhizal fungi (AMF); however, its role in LCO responses has not yet been studied. Here, we show that SlLYK10 proteins produced by the Sllyk10-1 and Sllyk10-2 mutant alleles, which both cause decreases in AMF colonization and carry mutations in LysM1 and 2, respectively, have similar LCO-binding affinities compared to the WT SlLYK10. However, the mutant forms were no longer able to induce cell death in Nicotiana benthamiana when co-expressed with MtLYK3, a Medicago truncatula LCO co-receptor, while they physically interacted with MtLYK3 in co-purification experiments. This suggests that the LysM mutations affect the ability of SlLYK10 to trigger signaling through a potential co-receptor rather than its ability to bind LCOs. Interestingly, tomato lines that contain a calcium (Ca2+) concentration reporter [genetically encoded Ca2+ indicators (GECO)], showed Ca2+ spiking in response to LCO applications, but this occurred only in inner cell layers of the roots, while short-chain chitooligosaccharides also induced Ca2+ spiking in the epidermis. Moreover, LCO-induced Ca2+ spiking was decreased in Sllyk10-1 * GECO plants, suggesting that the decrease in AMF colonization in Sllyk10-1 is due to abnormal LCO signaling. [ABSTRACT FROM AUTHOR]

Salt stress is one of the dominant abiotic stress conditions that cause severe damage to plant growth and, in turn, limiting crop productivity. It is therefore crucial to understand the molecular mechanism underlying plant root responses to high salinity as such knowledge will aid in efforts to develop salt-tolerant crops. Alternative splicing (AS) of precursor RNA is one of the important RNA processing steps that regulate gene expression and proteome diversity, and, consequently, many physiological and biochemical processes in plants, including responses to abiotic stresses like salt stress. In the current study, we utilized high-throughput RNA-sequencing to analyze the changes in the transcriptome and characterize AS landscape during the early response of tomato root to salt stress. Under salt stress conditions, 10,588 genes were found to be differentially expressed, including those involved in hormone signaling transduction, amino acid metabolism, and cell cycle regulation. More than 700 transcription factors (TFs), including members of the MYB, bHLH, and WRKY families, potentially regulated tomato root response to salt stress. AS events were found to be greatly enhanced under salt stress, where exon skipping was the most prevalent event. There were 3709 genes identified as differentially alternatively spliced (DAS), the most prominent of which were serine/threonine protein kinase, pentatricopeptide repeat (PPR)-containing protein, E3 ubiquitin-protein ligase. More than 100 DEGs were implicated in splicing and spliceosome assembly, which may regulate salt-responsive AS events in tomato roots. This study uncovers the stimulation of AS during tomato root response to salt stress and provides a valuable resource of salt-responsive genes for future studies to improve tomato salt tolerance. [ABSTRACT FROM AUTHOR]