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Plants face constant threats from pathogens, leading to growth retardation and crop failure. Cell-surface leucine-rich repeat receptor-like kinases (LRR-RLKs) are crucial for plant growth and defense, but their specific functions, especially to necrotrophic fungal pathogens, are largely unknown. Here, we identified an LRR-RLK (Solyc06g069650) in tomato (Solanum lycopersicum) induced by the economically important necrotrophic pathogen Botrytis cinerea. Knocking out this LRR-RLK reduced plant growth and increased sensitivity to B. cinerea, while its overexpression led to enhanced growth, yield, and resistance. We named this LRR-RLK as BRAK (B. cinerea resistance-associated kinase). Yeast two-hybrid screen revealed BRAK interacted with phytosulfokine (PSK) receptor PSKR1. PSK-induced growth and defense responses were impaired in pskr1, brak single and double mutants, as well as in PSKR1-overexpressing plants with silenced BRAK. Moreover, BRAK and PSKR1 phosphorylated each other, promoting their interaction as detected by microscale thermophoresis. This reciprocal phosphorylation was crucial for growth and resistance. In summary, we identified BRAK as a novel regulator of seedling growth, fruit yield and defense, offering new possibilities for developing fungal disease-tolerant plants without compromising yield. Synopsis: Plant growth and defense against pathogens are tightly regulated by receptor-like kinases (RLKs) located at the cell surface. This study identifies a novel leucine-rich repeat (LRR)-RLK in tomato, BRAK (Botrytiscinerea resistance-associated kinase), which simultaneously promotes plant growth and boosts resistance to the necrotrophic pathogen B. cinerea. BRAK promotes tomato seedling growth, fruit yield and defense against B. cinerea. BRAK interacts with the phytosulfokine (PSK) receptor PSKR1, and BRAK-regulated growth and defense is related to the PSK signaling pathway. Reciprocal phosphorylation between BRAK and PSKR1 is critical for growth and defense. The trade-off between pathogen resistance and growth is bypassed by the interaction between two membrane kinases. [ABSTRACT FROM AUTHOR]

Meloidogyne spp. are the most devastating plant‐parasitic nematodes affecting tomato worldwide. Although resistant cultivars and rootstocks are used, selection for virulence occurs in the pathogen. Consequently, using other resistance sources, such as Solanumtorvum, could improve resistance durability. Several experiments in microplots and plastic greenhouses were carried out to determine the potential use of S. torvum as a tomato rootstock to protect against M. incognita and M. javanica. In microplots, the relationship between nematode density at transplanting (Pi) and multiplication rate did not differ between Meloidogyne species in either ungrafted or grafted tomato. However, maximum multiplication rate and maximum density on grafted tomato were 1.27% and 2.93% those on ungrafted, respectively. The grafted tomato plants yielded between 2.9 and 7.5 more times than the ungrafted plants at Pi ≥ 100 eggs + J2s per 100 cm3 of soil, but no differences were observed in plastic greenhouse where a large amount of scion‐rooting occurred. In microplots, the quality of the tomato fruits of ungrafted and grafted plants was affected by the Pi. In parallel, some pot experiments were conducted on S. torvum and susceptible eggplant to determine the putative selection for nematode virulence to S. torvum and the nematode fitness cost. These showed that the nematode subpopulations infected and reproduced less on S. torvum than on eggplant. However, the female fertility was only reduced after development of three or four subpopulations on S. torvum. Finally, a histopathological study showed that nematode infection and development in S. torvum was delayed compared to eggplant. [ABSTRACT FROM AUTHOR]

Soil salinity is a serious concern for tomato culture, affecting both yield and quality parameters. Although some genes involved in tomato salt tolerance have been identified, their genetic diversity has been rarely studied. In the present study, we assessed salt tolerance‐related traits at juvenile and adult stages in a large core collection and identified salt tolerance quantitative trait loci (QTLs) by genome‐wide association study (GWAS). The results suggested that a major QTL is involved in leaf sodium accumulation at both physiological stages. We were able to identify the underlying candidate gene, coding for a well‐known sodium transporter, called SlHKT1.2. We showed that an eQTL for the expression of this gene in roots colocalized with the above ground sodium content QTL. A polymorphism putatively responsible for its variation was identified in the gene promoter. Finally, to extend the applicability of these results, we carried out the same analysis on a test‐cross panel composed of the core collection crossed with a distant line. The results indicated that the identified QTL retained its functional impact even in a hybrid genetic context: this paves the way for its use in breeding programs aimed at improving salinity tolerance in tomato cultivars. Summary Statement: The genetic diversity of sodium accumulation in tomato shoot under salt stress is associated with an expression QTL of SlHKT1.2. This gene, already identified as involved in tomato salinity tolerance, has been differentially selected during domestication and is of interest for the development of salinity‐tolerant varieties. [ABSTRACT FROM AUTHOR]

SUMMARY Fruit morphogenesis is determined by the coordination of cell division and expansion, which are fundamental processes required for the development of all plant organs. Here, we show that the regulation of TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) LANCEOLATE (TCP2/LA) by miR319 is crucial for tomato fruit morphology. The loss of miR319 regulation in the semi‐dominant La mutant led to a premature SlTCP2/LA expression during gynoecium patterning, which results in modified cell division during carpel development. As a consequence, La mutants exhibited elongated ovary and fruit shape, and a reduced number of ovules and seeds. Elongated fruit shape in La may be partially due to the SlTCP2/LA‐mediated repression of OVATE activity in young floral buds. Further analysis showed that the de‐repression of SlTCP2/LA decreases auxin responses in young floral buds by directly repressing SlYUCCA4 expression, but SlTCP2/LA also acts in parallel with ENTIRE (E) to orchestrate fruit morphology and seed production. Our study defines a novel miRNA‐based molecular link between the domestication‐associated OVATE gene and auxin responses. Given the striking variation in fruit morphology among members of the Solanaceae family, fine‐tuning regulation of gene expression by miRNA coupled with modulation of auxin dynamics may be a common driver in the evolution of fruit shape diversity. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Agronomic uses of biochar have been intensely explored in the last 15 years. Recently, a new generation of biochar‐based fertilizers has been developed. Raw biochar (BCH), nitrogen‐enriched biochar (N + BCH) or urea were added to a coir fiber‐based substrate for tomato cultivation, to assess seed germination, growth and fruiting of two cultivars (Cuarenteno and Moneymaker).BCH stimulated seed germination and early radicle growth, possibly because of the presence of karrikins detected in both BCH and N‐BCH (0.039 and 0.044 mg kg−1, respectively). However, BCH reduced growth in adult plants in both cultivars, probably because of ammonium retention, causing low‐N‐stress‐related symptoms such as accumulation of flavonoids in the leaf. Urea was toxic for seed germination because of the fast release of ammonium, but caused a positive effect on adult plant growth and yield, increasing chlorophyll in both cultivars, quantum yield and ascorbic acid in cv. Cuarenteno, and decreasing flavonoids and peroxide in leaves of both cultivars. Unlike urea, N + BCH showed a positive impact on plant growth and yield, but without releasing high amounts of ammonium or negatively affecting seed germination. Nitrogen‐rich amendments reduced phosphorus and increased iron leaf content in both cultivars.BCH can be effectively used as a growth medium constituent in nurseries for seedling production, whereas N + BCH offers a promising alternative to urea or other nitrogen mineral fertilizers for crop cultivation. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

SUMMARY: Cold stress restricts the metabolic and physiological activities of plants, thereby affecting their growth and development. Although broad‐complex, tramtrack, and bric‐à‐brac (BTB) proteins are essential for diverse biological processes and stress responses, the mechanisms underlying BTB‐mediated cold responses remain not fully understood. Here, we characterize the function of the cold‐induced SlBTB19 protein in tomato (Solanum lycopersicum). Overexpression of SlBTB19 resulted in increased plant sensitivity to cold stress, whereas SlBTB19 knockout mutants exhibited a cold‐tolerance phenotype. Further analyses, including protein–protein interaction studies and cell‐free degradation assays, revealed that SlBTB19 interacts with and destabilizes the transcription factor SlWRKY2. Using virus‐induced gene silencing (VIGS) to silence SlWRKY2 in both wild‐type and slbtb19 mutants, we provided genetic evidence that SlWRKY2 acts downstream of SlBTB19 in regulating cold tolerance. Importantly, we demonstrated that SlWRKY2 positively regulates cold tolerance in a CRT/DRE binding factor (CBF)‐dependent manner. Under cold stress, SlWRKY2 binds to the W‐box in the CBF1 and CBF3 promoters, directly activating their expression. In summary, our findings identify a SlBTB19‐SlWRKY2 module that negatively regulates the CBF‐dependent cold tolerance pathway in tomato. Significance Statement: Our findings not only contribute to the broader understanding of the molecular basis of plant responses to cold stress but also highlight the importance of post‐transcriptional mechanisms in regulating these responses. In summary, we proposed an updated model: A cold‐induced BTB family protein SlBTB19 negatively regulates cold tolerance. SlBTB19 interacts with and facilitates the proteolysis of the SlWRKY2 protein. SlWRKY2 is a positive regulator of cold tolerance, which activates cold‐responsive genes SlCBFs. [ABSTRACT FROM AUTHOR]

To understand whether domestication had an impact on susceptibility and responsiveness to arbuscular mycorrhizal fungi (AMF) in tomato (Solanum lycopersicum), we investigated two tomato cultivars ("M82" and "Moneymaker") and a panel of wild relatives including S. neorickii, S. habrochaites and S. pennellii encompassing the whole Lycopersicon clade. Most genotypes revealed good AM colonisation levels when inoculated with the AMF Funneliformis mosseae. By contrast, both S. pennellii accessions analysed showed a very low colonisation, but with normal arbuscule morphology, and a negative response in terms of root and shoot biomass. This behaviour was independent of fungal identity and environmental conditions. Genomic and transcriptomic analyses revealed in S. pennellii the lack of genes identified within QTLs for AM colonisation, a limited transcriptional reprogramming upon mycorrhization and a differential regulation of strigolactones and AM‐related genes compared to tomato. Donor plants experiments indicated that the AMF could represent a cost for S. pennellii: F. mosseae could extensively colonise the root only when it was part of a mycorrhizal network, but a higher mycorrhization led to a higher inhibition of plant growth. These results suggest that genetics and functional traits of S. pennellii are responsible for the limited extent of AMF colonisation. Summary Statement: Contrary to our hypothesis (domesticated plants are less dependent on mycorrhization than their wild relatives), we found a very low AM colonisation and a negative growth response in Solanum pennelli. Genetic and functional traits were identified as responsible for the limited colonisation success. [ABSTRACT FROM AUTHOR]

SUMMARY: Long non‐coding RNAs (lncRNAs) play crucial roles in various biological processes in plants. However, the functional mechanism of lncRNAs in fruit ripening, particularly the transition from unripe to ripe stages, remains elusive. One such lncRNA1840, reported by our group, was found to have important role in tomato fruit ripening. In the present study, we gain insight into its functional role in fruit ripening. CRISPR‐Cas9 mediated lncRNA1840 mutants caused the delayed tomato fruit ripening. Notably, loss function of lncRNA1840 did not directly impact ethylene signaling but rather delay ethylene synthesis. Transcriptomic analysis revealed differences in the expression of ripening related genes in lncRNA1840 mutants, suggesting that it is involved in gene regulation of fruit ripening. We used Chromatin Isolation by RNA Purification (ChIRP)‐Seq to identify lncRNA1840 binding sites on chromatin. ChIRP‐seq suggested that lncRNA1840 had occupancy on 40 genes, but none of them is differentially expressed genes in transcriptomic analysis, which indicated lncRNA1840 might indirectly modulate the gene expression. ChIRP‐mass spectrometry analysis identified potential protein interactors of lncRNA1840, Pre‐mRNA processing splicing factor 8, highlighting its involvement in post‐transcriptional regulatory pathways. In summary, lncRNA1840 is key player in tomato plant growth and fruit ripening, with multifaceted roles in gene expression and regulatory networks. Significance Statement: Long non‐coding RNAs (lncRNAs) play important roles in various biological processes in plants, but the mechanism of action of lncRNAs during fruit ripening remains unexplored. lncRNA1840 was identified in tomato, which confirmed that it affected the ripening process of tomato fruit and achieved post‐transcriptional regulation by participating in alternative splicing, which improved the regulatory network of tomato fruit ripening and filled the gap of lncRNA in the field of fruit ripening. [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 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]

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]

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]

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]

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]

SUMMARY: Knotted1‐like homeodomain (KNOX) proteins are essential in regulating plant organ differentiation. Land plants, including tomato (Solanum lycopersicum), have two classes of the KNOX protein family, namely, class I (KNOX I) and class II KNOX (KNOX II). While tomato KNOX I proteins are known to stimulate chloroplast development in fruit, affecting fruit coloration, the role of KNOX II proteins in this context remains unclear. In this study, we employ CRISPR/Cas9 to generate knockout mutants of the KNOX II member, SlKN5. These mutants display increased leaf complexity, a phenotype commonly associated with reduced KNOX II activity, as well as enhanced accumulation of chloroplasts and chlorophylls in smaller cells within young, unripe fruit. RNA‐seq data analyses indicate that SlKN5 suppresses the transcriptions of genes involved in chloroplast biogenesis, chlorophyll biosynthesis, and gibberellin catabolism. Furthermore, protein–protein interaction assays reveal that SlKN5 physically interacts with three transcriptional repressors from the BLH1‐clade of BEL1‐like homeodomain (BLH) protein family, SlBLH4, SlBLH5, and SlBLH7, with SlBLH7 showing the strongest interaction. CRISPR/Cas9‐mediated knockout of these SlBLH genes confirmed their overlapping roles in suppressing chloroplast biogenesis, chlorophyll biosynthesis, and lycopene cyclization. Transient assays further demonstrate that the SlKN5–SlBLH7 interaction enhances binding capacity to regulatory regions of key chloroplast‐ and chlorophyll‐related genes, including SlAPRR2‐like1, SlCAB‐1C, and SlGUN4. Collectively, our findings elucidate that the KNOX II SlKN5‐SlBLH regulatory modules serve to inhibit fruit greening and subsequently promote lycopene accumulation, thereby fine‐tuning the color transition from immature green fruit to mature red fruit. Significance Statement: This study shed light on regulatory mechanisms of plastid development in fruits by demonstrating that the class II knotted‐like homeodomain protein SlKN5 negatively regulates chloroplast number and chlorophyll accumulation in tomato fruit development. SlKN5 interacts with BEL1‐like homeodomain protein SlBLH7 and its paralogs to suppress SlAPRR2‐like1 and chlorophyll biosynthetic genes, promoting the developmental shift from growth phase to onset of ripening. This highlights the crucial role of the SlKN5‐BLH module in the regulation of tomato fruit coloration. [ABSTRACT FROM AUTHOR]

Summary: The antagonistic roles of ethylene and auxin are well established, although the exact role of auxin in ripening regulation remains unclear. A metabolomic approach can be a strategy to understand the role of this phytohormone in improving tomato quality. This study used metabolomic approaches to investigate how the interaction between ethylene and auxin affects tomato fruit nutritional and sensorial quality, with a particular emphasis on aroma metabolites. Tomato (Solanum lycopersicum cv. Micro‐Tom) fruits were randomly grouped according to treatment with ethylene (ETHY), auxin (IAA), or both (ETHY + IAA) phytohormones. Fruits without treatment were grouped in CTRL. Ethylene and auxin treatments affected carbohydrates (fructose, sucrose, and glucose), organic acids (citric and malic acids), and amino acids (valine, asparagine, and GABA), with the main volatile organic compounds precursors positively impacting ETHY + IAA aroma compounds. In conclusion, the comparison of metabolome profiles suggests that auxin regulation may overlap the ethylene regulatory system. Furthermore, tomato fruits treated with both phytohormones maintained metabolic profiles similar to those of untreated fruits in delayed ripening conditions, besides the improved tomato aroma. [ABSTRACT FROM AUTHOR]

Plants have developed chemical defence strategies which can either be triggered in response to herbivory or by the exogenous application of phytohormones, such as methyl jasmonate (MeJa). Tuta absoluta is the main pest associated with tomatoes worldwide. However, studies on the impact of plant hormones on this system are still scarce. This study aimed to evaluate the chemotactic responses and oviposition of T. absoluta towards tomato plants induced by MeJa and herbivory injuries. We conducted dual‐choice olfactometry bioassays evaluating the response of virgin T. absoluta males and females exposed to plants with conspecifics (eggs and caterpillars) and sprayed with MeJa (0.5 mM) at 24, 48, 72 and 96 h after the treatments. We also evaluated the oviposition preference of mated T. absoluta with the chance of choosing plants exposed to water, herbivory and three phytohormone concentrations (0.1, 0.5 and 2.5 mM). The males were mostly responsive to plants with conspecifics, while the females preferred intact plants over those sprayed with MeJa and with the presence of eggs. Furthermore, plants with MeJa (0.5 and 2.5 mM) and injured by conspecifics had less oviposition by T. absoluta. The results show that spraying MeJa on tomato plants is a potential tool for managing and controlling the tomato moth. [ABSTRACT FROM AUTHOR]

Tomato is a popular vegetable worldwide; its production is highly threatened by infection with the potato spindle tuber viroid (PSTVd). We obtained the full‐length genome sequence of previously conserved PSTVd and inoculated it on four genotypes of semi‐cultivated tomatoes selected from a local tomato germplasm resource. SC‐5, which is a PSTVd‐resistant genotype, and SC‐96, which is a PSTVd‐sensitive genotype, were identified by detecting the fruit yield, plant growth, biomass accumulation, physiological indices, and PSTVd genome titer after PSTVd inoculation. A non‐target metabolomics study was conducted on PSTVd‐infected and control SC‐5 to identify potential anti‐PSTVd metabolites. The platform of liquid chromatography‐mass spectrometry detected 158 or 123 differential regulated metabolites in modes of positive ion or negative ion. Principal component analysis revealed a clear separation of the global metabolite profile between PSTVd‐infected leaves and control regardless of the detection mode. The potential anti‐PSTVd compounds, xanthohumol, oxalicine B, indole‐3‐carbinol, and rosmarinic acid were significantly upregulated in positive ion mode, whereas echinocystic acid, chlorogenic acid, and 5‐acetylsalicylic acid were upregulated in negative ion mode. Xanthohumol and echinocystic acid were detected as the most upregulated metabolites and were exogenously applied on PSTVd‐diseased SC‐96 seedlings. Both xanthohumol and echinocystic acid had instant and long‐term inhibition effect on PSTVd titer. The highest reduction of disease symptom was induced by 2.6 mg/L of xanthohumol and 2.0 mg/L of echinocystic acid after 10 days of leaf spraying, respectively. A superior effect was seen on echinocystic acid than on xanthohumol. Our study provides a statistical basis for breeding anti‐viroid tomato genotypes and creating plant‐originating chemical preparations to prevent viroid disease. [ABSTRACT FROM AUTHOR]

Water availability is a limiting factor to plant development and productivity. Many drought‐induced physiological processes that affect patterns of growth, biomass allocation, and ultimately, yield, are also regulated by the red/far‐red photoreceptor phytochromes (PHYs). However, as the mechanisms and responses to drought stress vary among plant developmental phases, it is reasonable to conjecture that PHY‐dependent morphophysiological responses to drought may be different according to the plant growth stage. In this study, we submitted tomato phyB1 mutant plants to water deficit in two distinct growth stages, during vegetative and flower‐bearing reproductive phases, comparing the morphophysiological development, fruit yield and quality to wild‐type (WT). In general, phyB1 plants overcome growth limitations imposed by water availability limitations during vegetative phase, being taller and leafier than WT. Restrictions to growth are less acute for both genotypes when water deficit occurs during reproductive phase compared to vegetative phase. phyB1 yield is lower when water is limited during reproductive phase, but its fruits accumulate more soluble solids, associated with better quality. These results highlight that drought‐induced modulations in tomato growth and yield are dependent upon PHYB1 regulation and the developmental phase when water deficit is applied. [ABSTRACT FROM AUTHOR]

SUMMARY: The intercellular space or apoplast constitutes the main interface in plant–pathogen interactions. Apoplastic subtilisin‐like proteases—subtilases—may play an important role in defence and they have been identified as targets of pathogen‐secreted effector proteins. Here, we characterise the role of the Solanaceae‐specific P69 subtilase family in the interaction between tomato and the vascular bacterial wilt pathogen Ralstonia solanacearum. R. solanacearum infection post‐translationally activated several tomato P69s. Among them, P69D was exclusively activated in tomato plants resistant to R. solanacearum. In vitro experiments showed that P69D activation by prodomain removal occurred in an autocatalytic and intramolecular reaction that does not rely on the residue upstream of the processing site. Importantly P69D‐deficient tomato plants were more susceptible to bacterial wilt and transient expression of P69B, D and G in Nicotiana benthamiana limited proliferation of R. solanacearum. Our study demonstrates that P69s have conserved features but diverse functions in tomato and that P69D is involved in resistance to R. solanacearum but not to other vascular pathogens like Fusarium oxysporum. Significance Statement: The Solanaceae‐specific P69 subtilase family participates in the interaction between tomato and the vascular bacterial wilt pathogen Ralstonia solanacearum. [ABSTRACT FROM AUTHOR]

Plants employ a multilayered immune system to combat pathogens. In one layer, recognition of Pathogen‐ or Microbe‐Associated Molecular Patterns or elicitors, triggers a cascade that leads to defence against the pathogen and Pattern Triggered Immunity. Secondary or specialised metabolites (SMs) are expected to play a role, because they are potentially anti‐fungal compounds. Tomato (Solanum lycopersicum) plants inoculated with Alternaria solani s.l. show symptoms of infection after inoculation. Plants inoculated with Alternaria alternata remain symptomless. We hypothesised that pattern‐triggered induction of resistance related metabolites in tomato contributes to the resistance against A. alternata. We compared the metabolomic profile (metabolome) of tomato after treatments with A. alternata, A. solani and the fungal elicitor chitin, and identified SMs involved in early defence of tomato plants. We revealed differential metabolome fingerprints. The composition of A. alternata and chitin induced metabolomes show larger overlap with each other than with the A. solani induced metabolome. We identify 65 metabolites possibly associated with PTI in tomato plants, including NAD and trigonelline. We confirm that trigonelline inhibits fungal growth in vitro at physiological concentrations. Thus, a true pattern‐triggered, chemical defence is mounted against A. alternata, which contains anti‐fungal compounds that could be interesting for crop protection strategies. Summary statement: Using an untargeted metabolomics approach, comparing virulent, avirulent interactions and elicitor ‐treated samples, we identify new antifungal compounds in tomato that can be associated with pattern‐triggered immunity. [ABSTRACT FROM AUTHOR]

Drought strongly limits tomato yield, and the introgression of genes from wild tomatoes is a powerful tool to obtain drought‐tolerant progenies. The aim of this study was to select drought‐tolerant transgressive progeny obtained from interspecific crosses between drought‐susceptible tomatoes (Solanum lycopersicum) × drought‐tolerant wild species (Solanum pennellii) under in vitro and greenhouse conditions. BC1F2 populations were advanced from backcrosses between F1 × Jumbo AG‐592 (cultivar for fresh consumption) and F1 × BRS Tospodoro (cultivar for industrial processing). For this, BC1F2 seeds were germinated in vitro and evaluated for tolerance to drought. Then, eight genotypes from each BC1F2 were selected and submitted to 14 days of drought (0% of water supply) or well‐watered (100% of water supply) in greenhouse conditions and evaluated for growth, water balance and gas exchanges. Using in vitro assays with mannitol‐induced drought proved to be effective for the initial screening of drought‐tolerant BC1F2 plants, while greenhouse experiments showed that drought decreased photosynthesis in all genotypes, but almost all the BC1F2 progenies had greater photosynthetic capacity, water balance and growth than their commercial parents. As a result, we selected six progenies for fresh consumption and six progenies for industrial processing with increased drought tolerance. [ABSTRACT FROM AUTHOR]

Summary: The tomato (Solanum lycopersicum) ripening inhibitor (rin) mutation is known to completely repress fruit ripening. The heterozygous (RIN/rin) fruits have extended shelf life, ripen normally, but have inferior taste/flavour. To address this, we used genome editing to generate newer alleles of RIN (rinCR) by targeting the K‐domain.Unlike previously reported CRISPR alleles, the rinCR alleles displayed delayed onset of ripening, suggesting that the mutated K‐domain represses the onset of ripening. The rinCR fruits had extended shelf life and accumulated carotenoids at an intermediate level between rin and progenitor line. Besides, the metabolites and hormonal levels in rinCR fruits were more akin to rin.To overcome the negative attributes of rin, we crossed the rinCR alleles with Nps1, a dominant‐negative phototropin1 mutant, which enhances carotenoid levels in tomato fruits. The resulting Nps1/rinCR hybrids had extended shelf life and 4.4–7.1‐fold higher carotenoid levels than the wild‐type parent.The metabolome of Nps1/rinCR fruits revealed higher sucrose, malate, and volatiles associated with tomato taste and flavour. Notably, the boosted volatiles in Nps1/rinCR were only observed in fruits bearing the homozygous Nps1 mutation. The Nps1 introgression into tomato provides a promising strategy for developing cultivars with extended shelf life, improved taste, and flavour. [ABSTRACT FROM AUTHOR]

This study's objective was to identify the anastomosis groups and pathogenicity of Rhizoctonia species from soil samples in tomato production areas of Antalya, Burdur, and Isparta provinces in the West Mediterranean Region of Türkiye during the 2022 season. Soil samples were gathered from tomato plant rhizospheres in 223 different greenhouses, and isolations were done from the soil using the baiting technique. According to the results of morphological characterization and sequence analysis of the internal transcribed spacers of the ribosomal DNA, 47 Rhizoctonia isolates were defined as binucleate and 21 isolates as multinucleate. The collection of binucleate Rhizoctonia (Ceratobasidium sp.) isolates included representatives of Anastomosis Group‐F (61.76%), AG‐A (1.47%), and an unidentified binucleate Rhizoctonia (Ceratobasidium sp.) (5.88%). Multinucleate R. solani included AG 4 HG‐I (26.47%) and AG 4 HG‐II (4.41%). Pathogenicity tests showed statistically significant differences in virulence between binucleate Rhizoctonia (Ceratobasidium sp.) isolates and multinucleate Rhizoctonia isolates. All R. solani AG 4 HG‐II isolates and most of the AG 4 HG‐I isolates were pathogenic, causing severe necrosis symptoms and damping off in tomato seedlings, but binucleate AG‐A and AG‐F isolates were nonpathogenic. This study is the first detailed report about Rhizoctonia species isolated from the soil of tomato plants grown in greenhouse production areas in Türkiye. [ABSTRACT FROM AUTHOR]

SUMMARY: Carotenoids are isoprenoid pigments indispensable for photosynthesis. Moreover, they are the precursor of apocarotenoids, which include the phytohormones abscisic acid (ABA) and strigolactones (SLs) as well as retrograde signaling molecules and growth regulators, such as β‐cyclocitral and zaxinone. Here, we show that the application of the volatile apocarotenoid β‐ionone (β‐I) to Arabidopsis plants at micromolar concentrations caused a global reprogramming of gene expression, affecting thousands of transcripts involved in stress tolerance, growth, hormone metabolism, pathogen defense, and photosynthesis. This transcriptional reprogramming changes, along with induced changes in the level of the phytohormones ABA, jasmonic acid, and salicylic acid, led to enhanced Arabidopsis resistance to the widespread necrotrophic fungus Botrytis cinerea (B.c.) that causes the gray mold disease in many crop species and spoilage of harvested fruits. Pre‐treatment of tobacco and tomato plants with β‐I followed by inoculation with B.c. confirmed the effect of β‐I in increasing the resistance to this pathogen in crop plants. Moreover, we observed reduced susceptibility to B.c. in fruits of transgenic tomato plants overexpressing LYCOPENE β‐CYCLASE, which contains elevated levels of endogenous β‐I, providing a further evidence for its effect on B.c. infestation. Our work unraveled β‐I as a further carotenoid‐derived regulatory metabolite and indicates the possibility of establishing this natural volatile as an environmentally friendly bio‐fungicide to control B.c. Significance Statement: Plants rely on a wide range of metabolites to coordinate their growth and to respond to environmental stimuli. The family of carotenoid‐cleavage products, apocarotenoids, is emerging as a source of growth‐regulating and signaling molecules conferring protection against abiotic and biotic stresses. We show that the apocarotenoid, β‐ionone, is a regulatory metabolite that reshapes Arabidopsis transcriptome and hormone content, increasing resistance to the necrotrophic fungus Botrytis cinerea (B.c.) in Arabidopsis, tobacco and tomato plants. [ABSTRACT FROM AUTHOR]

The stearoyl‐ACP desaturase (SACPD) is a key enzyme in the regulation of saturated to unsaturated fatty acid ratio, playing a crucial role in regulating membrane stability and fluidity, as well as photosynthesis efficiency, which makes it an important research focus in crop species.This study reports the characterization and molecular cloning of pale dwarf (pad), a new tomato (Solanum lycopersicum L.) T‐DNA recessive mutant, which exhibits a dwarf and chlorotic phenotype. Functional studies of the T‐DNA tagged gene were conducted, including phylogenetic analysis, expression and metabolomic analyses, and generation of CRISPR/Cas9 knockout lines.The cloning of T‐DNA flanking genomic sequences and a co‐segregation analysis found the pad phenotype was caused by a T‐DNA insertion disrupting the tomato homologue of the Arabidopsis SUPPRESSOR OF SALICYLIC ACID INSENSITIVITY 2 (SlSSI2), encoding a plastid localized isoform of SACPD. The phenotype of CRISPR/Cas9 SlSSI2 knockout lines confirmed that the morphological abnormalities in pad plants were due to SlSSI2 loss of function. Functional, metabolomic and expression analyses proved that SlSSI2 disruption causes deficiencies in 18:1 fatty acid desaturation and leads to diminished jasmonic acid (JA) content and increased salicylic acid (SA) levels.Overall, these results proved that SSI2 plays a crucial role in the regulation of polyunsaturated fatty acid profiles in tomato, and revealed that SlSSI2 loss of function results in an inhibited JA‐responsive signalling pathway and a constitutively activated SA‐mediated defence signalling response. This study lays the foundation for further research on tomato SACPDs and their role in plant performance and fitness. [ABSTRACT FROM AUTHOR]

Hydrotropism is an important adaptation of plant roots to the uneven distribution of water, with current research mainly focused on Arabidopsis thaliana. To examine hydrotropism in tomato (Solanum lycopersicum) primary roots, we used RNA sequencing to determine gene expression of root tips (apical 5 mm) on dry and wet sides of hydrostimulated roots grown on agar plates. Hydrostimulation enhances cell division and expansion on the dry side compared with the wet side of the root tip. In hydrostimulated roots, the abscisic acid (ABA) biosynthesis gene ABA4 was induced more on the dry than the wet side of root tips. The ABA biosynthesis inhibitor Fluridone and the ABA‐deficient mutant notabilis (not) significantly decreased hydrotropic curvature. Wild‐type, but not the ABA biosynthesis mutant not, root tips showed asymmetric H+ efflux, with greater efflux on the dry than on the wet side of root tips. Thus, ABA mediates asymmetric H+ efflux, allowing the root to bend towards the wet side to take up more water. Summary statement: ABA regulates asymmetric H+ efflux, which is required for the root hydrotropic bending. [ABSTRACT FROM AUTHOR]

A high frequency of plants showing symptoms of wilting and root rot has been observed in tomato‐producing areas in Santarém and Belterra, Pará, Brazil. These plants showed symptoms ranging from yellowing to wilting, with roots displaying reduced development and darkening of the xylem. Four fungal isolates, derived from a collection of 12 obtained from symptomatic plants, were chosen for identification using both morphological and phylogenetic species concepts. To determine the identity of the fungi, DNA was extracted and used in PCR reactions. PCR products were sequenced from the TEF‐1α and RBP2 regions and compared with sequences in GenBank using BLASTn. Based on the phylogenetic analyses, the isolates were identified as Fusarium falciforme and Fusarium suttonianum, belonging to the species complex Fusarium solani – (FSSC), and Fusarium triseptatum, belonging to the species complex Fusarium oxysporum – (FOSC). The fourth isolate, COUFPI 295, grouped within a clade of F. kalimantanense and F. sangayamense from FOSC. The fulfilment of Koch's postulates confirmed that all isolates induced symptoms of root rot and concomitant reduction in root mass, leading to observable wilting symptoms. This is the first report of F. suttonianum, F. falciforme and F. triseptatum causing root rot and wilt in tomato plants in Brazil. [ABSTRACT FROM AUTHOR]

SUMMARY: Plant intracellular immune receptors, primarily nucleotide‐binding, leucine‐rich repeat proteins (NLRs), detect pathogen effector proteins and activate NLR‐triggered immunity (NTI). Recently, 'sensor' NLRs have been reported to function with 'helper' NLRs to activate immunity. We investigated the role of two helper NLRs, Nrc2 and Nrc3, on immunity in tomato to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) mediated by the sensor NLR Prf and the Pto kinase. An nrc2/nrc3 mutant no longer activated Prf/Pto‐mediated NTI to Pst containing the effectors AvrPto and AvrPtoB. An nrc3 mutant showed intermediate susceptibility between wild‐type plants and a Prf mutant, while an nrc2 mutant developed only mild disease. These observations indicate that Nrc2 and Nrc3 act additively in Prf‐/Pto‐mediated immunity. We examined at what point Nrc2 and Nrc3 act in the Prf/Pto‐mediated immune response. In the nrc2/3 mutant, programmed cell death (PCD) normally induced by constitutively active variants of AvrPtoB, Pto, or Prf was abolished, but that induced by M3Kα or Mkk2 was not. PCD induced by a constitutively active Nrc3 was also abolished in a Nicotiana benthamiana line with reduced expression of Prf. MAPK activation triggered by expression of AvrPto in the wild‐type tomato plants was completely abolished in the nrc2/3 mutant. These results indicate that Nrc2 and Nrc3 act with Prf/Pto and upstream of MAPK signaling. Nrc2 and Nrc3 were not required for PCD triggered by Ptr1, another sensor NLR‐mediating Pst resistance, although these helper NLRs do appear to be involved in resistance to certain Pst race 1 strains [ABSTRACT FROM AUTHOR]

Climate change exacerbates abiotic stresses like salinization, negatively impacting crop yield, so development of strategies, like using salt‐tolerant rootstocks, is crucial. The CALCINEURIN B‐LIKE 10 (SlCBL10) gene has been previously identified as a positive regulator of salt tolerance in the tomato shoot. Here, we report a different function of SlCBL10 in tomato shoot and root, as disruption of SlCBL10 only induced salt sensitivity when it was used in the scion but not in the rootstock. The use of SlCBL10 silencing rootstocks (Slcbl10 mutant and RNAi line) improved salt tolerance on the basis of fruit yield. These changes were associated with improved Na+ and K+ homoeostasis, as SlCBL10 silencing reduced the Na+ content and increased the K+ content under salinity, not only in the rootstock but also in the shoot. Improvement of Na+ homoeostasis in Slcbl10 rootstock seems to be mainly due to induction of SlSOS1 expression, while the higher K+ accumulation in roots seems to be mainly determined by expression of LKT1 transporter and SlSKOR channel. These findings demonstrate that SlCBL10 is a negative regulator of salt tolerance in the root, so the use of downregulated SlCBL10 rootstocks may provide a suitable strategy to increase tomato fruit production under salinity. Summary statement: A novel function of SlCBL10 in tomato root is reported, as the gene silencing rootstock improve salt tolerance of the shoot genotype throughout growth cycle resulting in higher fruit yield. The salt tolerance is related to improved Na+/K+ homoeostasis via upregulated expression of SlSOS1 for Na+ and LKT1 and SlSKOR for K+. [ABSTRACT FROM AUTHOR]

Drought resistance is essential for plant production under water‐limiting environments. Abscisic acid (ABA) plays a critical role in stomata but its impact on hydraulic function beyond the stomata is far less studied. We selected genotypes differing in their ability to accumulate ABA to investigate its role in drought‐induced dysfunction. All genotypes exhibited similar leaf and stem embolism resistance regardless of differences in ABA levels. Their leaf hydraulic resistance was also similar. Differences were only observed between the two extreme genotypes: sitiens (sit; a strong ABA‐deficient mutant) and sp12 (a transgenic line that constitutively overaccumulates ABA), where the water potential inducing 50% embolism was 0.25 MPa lower in sp12 than in sit. Maximum stomatal and minimum leaf conductances were considerably lower in plants with higher ABA (wild type [WT] and sp12) than in ABA‐deficient mutants. Variations in gas exchange across genotypes were associated with ABA levels and differences in stomatal density and size. The lower water loss in plants with higher ABA meant that lethal water potentials associated with embolism occurred later during drought in sp12 plants, followed by WT, and then by the ABA‐deficient mutants. Therefore, the primary pathway by which ABA enhances drought resistance is via declines in water loss, which delays dehydration and hydraulic dysfunction. Summary statement: The impact of abscisic acid on the drought tolerance of young plants of tomato is essentially associated with stomatal function, and not with xylem resistance to embolism. [ABSTRACT FROM AUTHOR]

BACKGROUND: High tunnels (HT) and plastic mulch can increase yield, extend growing seasons, protect plants from harsh weather conditions, and produce more marketable and attractive tomatoes. However, plastic covering reduces solar radiation, which may affect the quality of tomatoes. This study investigated the effects of single‐layer versus double‐layer HT and plastic mulch versus bare soil on the quality of fully ripe tomato fruits. The study was conducted over 2 years (2021 and 2022). The fruit color (L*, a*, and b*), vitamin C, pH, total titratable acid (TTA), total soluble solids (TSS), and lycopene content of the two tomato cultivars (Brandywine and Rebelski) were quantified. RESULTS: The results showed that quality parameters varied with the plastic layers of HT, plastic mulch, and planting year. The double‐layer HT only showed a slight but significant influence on the color of tomatoes of both cultivars in the same year (P < 0.05). Brandywine tomatoes grown in the double‐layer HT had significantly lower pH and lycopene content than those grown in single‐layer HT, regardless of mulching. The effect of plastic layers on TTA, TSS, and lycopene depended on whether the soil was mulched. Tomatoes grown on bare soil had higher TTA and TSS values than those grown on mulched soil in double‐layer HT. Tomatoes grown in single‐layer HTs had significantly higher vitamin C content than those in the double‐layer HT for both cultivars regardless of mulching. CONCLUSION: This study demonstrates that double‐layer HT is unnecessary for the improvement of the overall quality of tomatoes. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

SUMMARY: Diurnal rhythms are known to regulate the expression of a large number of genes, coordinating plant growth and development with diel changes in light and temperature. However, the impact of RNA metabolism on rhythmic gene oscillations in plant is not yet fully understood. To address this question, we performed transcriptome and degradome profiling on tomato leaves at 6 time points during one 24 h cycle, using RNA‐seq and genome‐wide mapping of uncapped and cleavage transcripts (GMUCT). Time‐series profiling of RNA‐seq revealed 9342 diurnal‐oscillated genes, which were enriched in various metabolic processes. To quantify the general level of RNA degradation for each gene, we utilized the Proportion Uncapped (PU) metric, which represents the GMUCT/RNA‐seq ratio. Oscillated PU analysis revealed that 3885 genes were regulated by rhythmic RNA degradation. The RNA decay of these diurnal genes was highly coordinated with mRNA downregulation during oscillation, highlighting the critical role of internal transcription‐degradation balance in rhythmic gene oscillation. Furthermore, we identified 2190 genes undergoing co‐translational RNA decay (CTRD) with 5′ phosphate read ends enriched at the boundary of ribosomes stalling at translational termination sites. Interestingly, diurnal‐changed mRNAs with large amplitudes tended to be co‐translationally decay, suggesting that CTRD contributed to the rapid turnover of diurnal mRNAs. Finally, we also identified several genes, whose miRNA cleavage efficiency oscillated in a diurnal manner. Taken together, these findings uncovered the vital functions of RNA metabolism, including rhythmic RNA degradation, CTRD, and miRNA cleavage, in modulating the diurnal mRNA oscillations during diel change at post‐transcriptional level in tomato. Significance Statement: RNA metabolism, including rhythmic RNA degradation, co‐translational RNA decay, and miRNA cleavage, played a vital role in modulating diurnal mRNA oscillations at the post‐transcriptional level in tomato. [ABSTRACT FROM AUTHOR]

Plant Na+/H+antiporter (NHX) genes enhance salt tolerance by preventing excessive Na+ accumulation in the cytosol through partitioning of Na+ ions into vacuoles or extracellular transport across the plasma membrane. However, there is limited detailed information regarding the salt stress responsive SlNHXs in the most recent tomato genome. We investigated the role of this gene family's expression patterns in the open flower tissues under salt shock in Solanum lycopersicum using a genome‐wide approach. A total of seven putative SlNHX genes located on chromosomes 1, 4, 6, and 10 were identified, but no ortholog of the NHX5 gene was identified in the tomato genome. Phylogenetic analysis revealed that these genes are divided into three different groups. SlNHX proteins with 10–12 transmembrane domains were hypothetically localized in vacuoles or cell membranes. Promoter analysis revealed that SlNHX6 and SlNHX8 are involved with the stress‐related MeJA hormone in response to salt stress signaling. The structural motif analysis of SlNHX1, −2, −3, −4, and −6 proteins showed that they have highly conserved amiloride binding sites. The protein–protein network revealed that SlNHX7 and SlNHX8 interact physically with Salt Overly Sensitive (SOS) pathway proteins. Transcriptome analysis demonstrated that the SlNHX2 and SlNHX6 genes were substantially expressed in the open flower tissues. Moreover, quantitative PCR analysis indicated that all SlNHX genes, particularly SlNHX6 and SlNHX8, are significantly upregulated by salt shock in the open flower tissues. Our results provide an updated framework for future genetic research and development of breeding strategies against salt stress in the tomato. [ABSTRACT FROM AUTHOR]

BACKGROUND: The role of plant flavonoids in direct defences against chewing and sap‐sucking herbivorous insects has been extensively characterized. However, little is known about flavonoid‐mediated tritrophic interactions between plants, herbivorous insects and natural enemies. In this study, we investigated how flavonoids modulate plant–insect interactions in a tritrophic system involving near‐isogenic lines (NILs) of cultivated tomato (Solanum lycopersicum) with high (line NIL‐purple hypocotyl [PH]) and low (line NIL‐green hypocotyl [GH]) flavonoid levels, with a generalist herbivore whitefly (Bemisia tabaci) and its predatory bug (Orius sauteri). RESULTS: By contrasting levels of tomato flavonoids (direct defence) while manipulating the presence of predators (indirect defence), we found that high production of flavonoids in tomato was associated with a higher inducibility of direct defences and a stronger plant resistance to whitefly infestation and stimulated the emissions of induced volatile organic compounds, thereby increasing the attractiveness of B. tabaci‐infested plants to the predator O. sauteri. Furthermore, suppression of B. tabaci population growth and enhancement of plant growth were mediated directly by the high production of flavonoids and indirectly by the attraction of O. sauteri, and the combined effects were larger than each effect individually. CONCLUSION: Our results show that high flavonoid production in tomato enhances herbivore‐induced direct and indirect defences to better defend against herbivores in tritrophic interactions. Thus, the development of transgenic plants may present an opportunity to utilize the beneficial role of flavonoids in integrated pest management, while simultaneously maintaining or improving resistance against other pests and pathogens. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Plant defense traits such as trichomes along with biocontrol agents may provide alternatives to insecticide use in tomatoes, Solanum lycopersicum L. (Solanaceae). However, plant‐herbivore‐natural enemy interactions are not always complementary. In a series of greenhouse and field experiments, we explored whether augmented defense traits (i.e., production of acylsugars) in tomato plants could reduce sweet potato whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), populations and aid the establishment of the predatory mite Amblyseius swirskii Athias‐Henriot (Acari: Phytoseiidae). In the field experiment, commercial tomato cultivars and acylsugar‐producing tomato lines received no predatory mites or mites released via three methods: dusting on top, dusting on bottom, or slow‐release sachets. In the first greenhouse experiment, predatory mites were released onto the commercial and acylsugar‐producing tomato plants via sachets. In the second greenhouse experiment using a similar design, we augmented the mite diet with an alternative non‐prey resource (i.e., cattail pollen). Our results indicated that acylsugar‐producing tomato plants supported significantly fewer whiteflies than the commercial lines in all experiments. However, in the field, despite lower whitefly numbers, Tomato yellow leaf curl virus (TYLCV) (Geminiviridae, Begomovirus) was detected at higher frequencies in acylsugar‐producing lines. Few mites were recovered from all commercial and acylsugar‐producing lines in the field or greenhouse experiments suggesting A. swirskii does not establish well on tomatoes, and acylsugar lines successfully decreased whitefly populations but not a viral disease transmitted even at low whitefly abundance. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tomato (Solanum lycopersicum) has a relatively short shelf life as a result of rapid ripening, limiting its transportability and marketability. Recently, gamma irradiation has emerged as a viable method for delaying tomato fruit ripening. Although few studies have shown that gamma irradiation delays the ripening of tomatoes, the underlying mechanism remains unknown. Therefore, the present study aimed to examine the effects of gamma irradiation on tomato fruit ripening and the underlying mechanisms using transcriptomics. RESULTS: Following gamma irradiation, the total microbial count, weight loss, and decay rate of tomatoes significantly reduced during storage. Furthermore, the redness (a*), color change (∆E), and lycopene content of gamma‐irradiated tomatoes decreased in a dose‐dependent manner during storage. Moreover, gamma irradiation significantly upregulated the expression levels of genes associated with DNA, chloroplast, and oxidative damage repairs, whereas those of ethylene and auxin signaling‐, ripening‐, and cell wall metabolism‐related, as well as carotenoid genes, were downregulated. CONCLUSION: Gamma irradiation effectively delayed ripening by downregulating the expression of ripening‐related genes and inhibiting microbial growth, which prevented decay and prolonged the shelf life of tomatoes. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Soil cultivation may change the soil microbiome and alter interactions between plants and parasites. This work aimed to evaluate temporal changes in plant health, soil microbiome abundance and incidence of the emergent plant‐parasitic nematode, Meloidogyne enterolobii, in two soil fields with different agricultural uses. Soil samples were collected from a commercial tomato production field (agricultural soil) and a single‐cultivation strawberry field (native soil) for two successive years. Tomato plants cv. Early Girl were grown in a greenhouse, and three groups of inoculums were used: Fusarium only, M. enterolobii only and Fusarium + M. enterolobii. After 45 days, plants were evaluated for growth parameters and nematode reproduction and soil bacterial assemblages were assessed using cultivation‐independent sequencing methods (V3/V4 region of the 16S rRNA). Among both soil types, the average root fresh weight increased (56%), along with shoot fresh weight (82%) and fruit fresh weight (76%) in the second year. Moreover, there was an 80.5% decrease in eggs present per root system from the first year to the second. The relative abundance of bacterial assemblages from Year 1 to Year 2 changed for most of the top phyla (e.g., Actinobacteria, Bacteroidetes and Chloroflexi) and genera (e.g., Bacillus, Streptomyces and Flavisolibacter). This study suggests that soil management and year‐to‐year variation can lead to a shift in overall bacterial assemblages, better crop yield and an overall decrease in nematode reproduction. [ABSTRACT FROM AUTHOR]

SUMMARY: Low temperature and abscisic acid (ABA) are the two main factors that induce anthocyanin synthesis; however, their potential relationships in governing anthocyanin biosynthesis in Solanum lycopersicum (tomato) seedlings remains unclear. Our study revealed the involvement of the transcription factor SlAREB1 in the low‐temperature response of tomato seedlings via the ABA‐dependent pathway, for a specific temperature range. The overexpression of SlAREB1 enhanced the expression of anthocyanin‐related genes and the accumulation of anthocyanins, especially under low‐temperature conditions, whereas silencing SlAREB1 dramatically reduced gene expression and anthocyanin accumulation. There is a direct interaction between SlAREB1 and the promoters of SlDFR and SlF3′5′H, which are structural genes that impact anthocyanin biosynthesis. SlAREB1 can regulate anthocyanins through controlling SlDFR and SlF3′5′H expression. Accordingly, SlAREB1 takes charge of regulating anthocyanin biosynthesis in tomato seedlings via the ABA‐dependent pathway at low temperatures. Significance Statement: Temperature and abscisic acid are two important factors inducing anthocyanin biosynthesis, but usually they have been studied independently in the past. In our experiment, we found that SlAREB1, an important transcription factor of the ABA‐dependent signaling pathway, is involved in low‐temperature‐induced anthocyanin biosynthesis, thereby improving our understanding of this regulatory network. [ABSTRACT FROM AUTHOR]

Plants have evolved well‐tuned surveillance systems, including complex defence mechanisms, to constrain pathogens. TFs are master regulators of host molecular responses against plant pathogens. While PepMV constitutes a major threat to the global tomato production, there is still a lack of information on the key TFs that regulate host responses to this virus.A combinatorial research approach was applied relying on tomato transcriptome analysis, RT‐qPCR validation, phylogenetic classification, comparative analysis of structural features, cis‐regulatory element mining and in silico co‐expression analysis to identify a set of 11 highly responsive TFs involved in the regulation of host responses to PepMV.An endemic PepMV isolate, generating typical mosaic symptoms, modified expression of ca. 3.3% of tomato genes, resulting in 1,120 DEGs. Functional classification of 502 upregulated DEGs revealed that photosynthesis, carbon fixation and gene silencing were widely affected, whereas 618 downregulated genes had an impact mainly on plant defence and carotenoid biosynthesis. Strikingly, all 11 highly responsive TFs carried abiotic stress response cis‐regulatory elements, whereas five of them were better aligned with rice than with Arabidopsis gene homologues, suggesting that plant responses against viruses may predate divergence into monocots and dicots. Interestingly, tomato C2H2 family TFs, ZAT1‐like and ZF2, may have distinct roles in plant defence due to opposite response patterns, similar to their Arabidopsis ZAT10 and ZAT12 homologues.These highly responsive TFs provide a basis to study in‐depth molecular responses of the tomato–PepMV pathosystem, providing a perspective to better comprehend viral infections. [ABSTRACT FROM AUTHOR]

Summary: Cuticles are multifunctional hydrophobic biocomposites that protect the aerial organs of plants. During plant development, plant cuticles must accommodate different mechanical constraints combining extensibility and stiffness, and the corresponding relationships with their architecture are unknown. Recent data showed a fine‐tuning of cuticle architecture during fruit development, with several chemical clusters which raise the question of how they impact the mechanical properties of cuticles.We investigated the in‐depth nanomechanical properties of tomato (Solanum lycopersicum) fruit cuticle from early development to ripening, in relation to chemical and structural heterogeneities by developing a correlative multimodal imaging approach.Unprecedented sharps heterogeneities were evidenced including an in‐depth mechanical gradient and a 'soft' central furrow that were maintained throughout the plant development despite the overall increase in elastic modulus. In addition, we demonstrated that these local mechanical areas are correlated to chemical and structural gradients.This study shed light on fine‐tuning of mechanical properties of cuticles through the modulation of their architecture, providing new insight for our understanding of structure–function relationships of plant cuticles and for the design of bioinspired material. [ABSTRACT FROM AUTHOR]

BACKGROUND: Host plant resistance plays an important role in integrated pest management programs. Crop resistance assessments commonly focus on only a single dependent variable, such as larval survival/plant damage, which limits the ability to appreciate the impact of host plants on pest populations in the full sense. Therefore, we performed life‐table analyses for tomato leaf miner Tuta absoluta, on 19 Solanum lycopersicum genotypes and a wild Solanum habrochaites accession. These analyses assess the ability of the pest to attain a high population density on different tomato genotypes. Based on the resulting ranking of tomato resistance at the vegetative stage (45‐day‐old plants), we tested the resistance of six selected genotypes at the reproductive stage (4‐month‐old plants). RESULTS: T. absoluta performance was significantly inferior on vegetative‐stage S. habrochaites plants (LA 1777); time taken for the first instars to mine the leaves (5 ± 0.14 days), development time of early‐ and late‐stage larvae (8.8 ± 0.2 and 4.2 ± 0.2 days, respectively), pupal period (11.2 ± 0.58 days), and total developmental time (29.4 ± 0.83 days) were significantly longer, fecundity was significantly lower (18.66 ± 7.24 days), and the highest total mortality (63.33%) also recorded compared with other genotypes, resulting in the lowest net reproductive rate (R0) (11.20 ± 2.51). For the six selected genotypes, the ranking of plant resistance did not change between plants at the vegetative and reproductive stages. CONCLUSION: This study suggested that of 20 screened tomato genotypes, LA 1777 and EC‐620343 are the least suitable hosts for T. absoluta to establish fast‐growing populations, and thus can be employed in integrated T. absoluta management. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

SUMMARY: A level of redundancy and interplay among the transcriptional regulators of floral development safeguards a plant's reproductive success and ensures crop production. In the present study, an additional layer of complexity in the regulation of floral meristem (FM) identity and flower development is elucidated linking carotenoid biosynthesis and metabolism to the regulation of determinate flowering. The accumulation and subsequent cleavage of a diverse array of ζ‐carotenes in the chloroplast biogenesis 5 (clb5) mutant of Arabidopsis results in the reprogramming of meristematic gene regulatory networks establishing FM identity mirroring that of the FM identity master regulator, APETALA1 (AP1). The immediate transition to floral development in clb5 requires long photoperiods in a GIGANTEA‐independent manner, whereas AP1 is essential for the floral organ development of clb5. The elucidation of this link between carotenoid metabolism and floral development translates to tomato exposing a regulation of FM identity redundant to and initiated by AP1 and proposed to be dependent on the E class floral initiation and organ identity regulator, SEPALLATA3 (SEP3). Significance Statement: In the present study, we aimed to explore how regulation of the multi‐enzyme poly‐cis‐transformation of 15 cis‐phytoene to all trans‐lycopene, which evolved from the single enzymatic reaction in bacteria, provides a unique means to regulate various aspects of plant development. As a result, a link between carotenoid biosynthesis and metabolism and the regulation of floral meristem identity and floral organ development in Arabidopsis and tomato is uncovered. [ABSTRACT FROM AUTHOR]

The tomato industry in South Florida (USA) is seriously affected by recently emerging Tomato chlorotic spot virus (TCSV). Western flower thrips, Frankliniella occidentalis (Pergande), and common blossom thrips, Frankliniella schultzei (Trybom) (Thysanoptera: Thripidae), are the two known vectors of TCSV in Florida. In the present study, the presence of thrips vectors and TCSV in 24 flowering ornamental plant species was observed in South Florida. The two thrips vectors, as well as melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae), were abundant in the area; they were observed with a range from high (83.1 per sample of 10 flowers) in Hibiscus rosa‐sinensis L. to low (3.7 per sample of 10 flowers) in Catharanthus roseus (L.) G. Don in a nursery study. In a subsequent greenhouse study, we selected seven species of ornamentals, among which the species with the highest thrips abundance, and planted them next to tomato, to determine their effects on TCSV incidence and thrips abundance in tomatoes. Tomatoes with Portulaca oleracea L. next to them showed a higher number of TCSV‐infected plants (4.25 plants per plot in 2017, and 3.25 plants per plot in 2018) compared to tomatoes with some of the other ornamentals next to them. We report the presence of TCSV through reverse transcriptase polymerase chain reaction (RT‐PCR) analysis in Lantana camara L., H. rosa‐sinensis, Mandevilla spec., Gazania linearis (Thunb.) Druce, Hemerocallis spec., Agastache spec., and P. oleracea. Identification of alternative hosts of TCSV and thrips vectors can be helpful to evaluate the ongoing management programs and develop future programs in local tomato‐growing areas. [ABSTRACT FROM AUTHOR]

Tomato crops are affected by various viral diseases. In Brazil, the most frequent of these diseases are caused by the begomovirus tomato severe rugose virus (ToSRV), the crinivirus tomato chlorosis virus (ToCV) and orthotospoviruses, mainly groundnut ringspot virus (GRSV) and tomato chlorotic spot virus (TCSV). Mixed infections can result in synergistic interactions and, in some cases, the breakdown of resistance, as previously reported for the interaction between ToCV and tomato spotted wilt virus (TSWV) in tomato plants carrying the Sw‐5 orthotospovirus‐resistance gene. This study evaluated the interaction between ToCV and the orthotospoviruses GRSV, TCSV and TSWV in tomato plants carrying the Sw‐5 gene, as well as the attractiveness of ToCV‐infected tomato plants to thrips in the field. Greenhouse assays demonstrated that the resistance to infection with GRSV and TCSV was overcome in 17% of the tomato plants previously infected with ToCV. In contrast, ToCV‐pre‐infected plants remained resistant to TSWV. Under field conditions, the incidence of orthotospoviruses was low in resistant tomato cultivars, even with a high incidence of ToCV‐infected tomato plants, indicating the effectiveness of the Sw‐5 gene. ToCV pre‐infection of tomato plants did not influence their attractiveness to thrips. In conclusion, pre‐infection with ToCV did not influence the effectiveness of the Sw‐5 resistance gene against GRSV under field conditions. [ABSTRACT FROM AUTHOR]

The Queensland fruit fly, Bactrocera tryoni, is an economically important pest insect of horticultural crops in Australia, damaging a wide variety of fruits and vegetables. To study the B. tryoni–fruit interaction, we conducted a transcriptomic investigation of B. tryoni larvae feeding on three ripening stages of tomato fruit, which had been previously shown to influence larval performance. Fruit fly larval survival in immature tomato fruit is very poor, which we hypothesized to be due to the effect of tomato fruit toxins which are mostly expressed in green fruit. We found 2709 transcripts differentially expressed in larvae feeding on the three ripening stages. The transcript expression pattern was most divergent between larvae feeding in immature fruit compared with fully ripe fruit, with intermediate expression in larvae feeding in colour‐break fruit. Gene Set Enrichment Analysis showed that larvae fed in immature fruit had a higher number of depleted GO terms in comparison with larvae fed on fully ripe fruit, particularly GO terms associated with larval development, metabolism and basic cellular functions. Enriched GO terms in larvae fed on fully ripe fruit showed the opposite pattern, with a greater number of enriched terms related to larval growth and detoxification processes. We concluded that poor larval survival in immature‐green fruit is likely because the substrate offers a very poor diet for larvae, which limits normal developmental functions. By contrast, in colour‐break and fully ripe fruit the substrate allows normal development, including the expression of metabolically costly detoxification mechanisms. [ABSTRACT FROM AUTHOR]

This article discusses the use of CRISPR/Cas9 technology to disrupt the CYC-B gene in tomato plants, resulting in increased lycopene content in the fruit and enhanced postharvest cold tolerance. The CYC-B gene is responsible for the catabolism of lycopene, a carotenoid pigment found in tomatoes. Previous mutations in the CYC-B gene only existed in determinate tomatoes, making it difficult to breed high-lycopene indeterminate tomatoes. The researchers successfully generated knockout variants of CYC-B in two indeterminate tomato genotypes, resulting in increased lycopene content and improved cold tolerance in the fruit. This study provides valuable insights into the potential use of CRISPR/Cas9 technology in tomato breeding and highlights the protective role of lycopene during postharvest cold storage. [Extracted from the article]

Phytosulfokine (PSK) is a plant pentapeptide hormone that fulfills a wide range of functions. Although PSK has frequently been reported to function in the inverse regulation of growth and defense in response to (hemi)biotrophic pathogens, the mechanisms involved remain largely unknown. Using the tomato (Solanum lycopersicum) and Pseudomonas syringae pv. tomato (Pst) DC3000 pathogen system, we present compelling evidence that the PSK receptor PSKR1 interacts with the calcium‐dependent protein kinase CPK28, which in turn phosphorylates the key enzyme of nitrogen assimilation glutamine synthetase GS2 at two sites (Serine‐334 and Serine‐360). GS2 phosphorylation at S334 specifically regulates plant defense, whereas S360 regulates growth, uncoupling the PSK‐induced effects on defense responses and growth regulation. The discovery of these sites will inform breeding strategies designed to optimize the growth‐defense balance in a compatible manner. Synopsis: The peptide hormone phytosulfokine (PSK) acts to promote plant growth at the expense of the pathogen defense against (hemi)biotrophic pathogens. Here, we show that the PSK‐induced phosphorylation of glutamine synthetase GS2 at two serine residues regulates this balance. CPK28 interacts with the PSK receptor PSKR1 and is required for PSK‐PSKR1 signaling‐mediated growth‐defense responses in tomato.PSK promotes the CPK28‐mediated phosphorylation of glutamine synthetase GS2 at Ser334 and Ser360.GS2 phosphorylation at Ser334 specifically regulates plant defense, whereas Ser360 regulates growth. [ABSTRACT FROM AUTHOR]