Exploring the potential of tomato juice (Solanum lycopersicum L.) patch for tooth bleaching.

Background: Tomato, renowned for its tooth-whitening properties due to its hydrogen peroxide and peroxidase enzyme content, requires formulation for enhanced applicability. This study assessed the dental whitening efficacy of a patch containing tomato juice as the active ingredient. Methods: Tomato juice patches were formulated at concentrations of 55%, 60%, and 65%. A control group (C) containing a 12% hydrogen peroxide patch was also included. A matrix layer of the patches was prepared using the solvent casting method at 40 for 18 h, with TegadermTM applied as the backing layer. For the dental whitening procedure, each group of patches was applied to the labial surface of anterior stained teeth (n=6/group) for 3 h, repeated 14 times. Tooth brightness was evaluated qualitatively and quantitatively using digital dental photo CIEL*a*b* analysis. Meanwhile, enamel surfaces were examined under a scanning electron microscope (SEM). Repeated-measures analysis of variance (ANOVA) was employed for statistical analysis. Results: The application of tomato juice patches led to enhanced tooth brightness. The patch containing 65% tomato juice significantly improved stained tooth brightness (P<0.05). SEM analysis revealed less enamel erosion with the 65% tomato juice patch compared to the 12% hydrogen peroxide patch. Conclusion: Tomato juice patches effectively increased tooth brightness while minimizing demineralization. Further research is needed to optimize formulation and explore its potential.

Convergent emergence of Glucomannan ß-galactosyltransferase activity in Asterids and Rosids.

ß-Galactoglucomannan (ß-GGM) is a primary cell wall polysaccharide in rosids and asterids. The ß-GGM polymer has a backbone of repeating ß-(1,4)-glucosyl and mannosyl residues, usually with mono- α-(1,6)-galactosyl substitution or ß-(1,2)-galactosyl α-galactosyl disaccharide sidechains on the mannosyl residues. Mannan ß-GalactosylTransferases (MBGTs) are therefore required for ß-GGM synthesis. The single MBGT identified so far, AtMBGT1, lies in glycosyltransferase family 47A subclade VII, and was identified in Arabidopsis. However, despite the presence of ß-GGM, an orthologous gene is absent in tomato (Solanum lycopersicum), a model asterid. In this study, we screened candidate MBGT genes from the tomato genome, functionally tested the activities of encoded proteins, and identified the tomato MBGT (SlMBGT1) in GT47A-III. Interestingly therefore, AtMBGT1 and SlMBGT1 are located in different GT47A subclades. Further, phylogenetic and glucomannan structural analysis from different species raised the possibility that various asterids possess conserved MBGTs in an asterid-specific subclade of GT47A-III, indicating that MBGT activity has been acquired convergently among asterids and rosids. The present study highlights the promiscuous emergence of donor and acceptor preference in GT47A enzymes. The independent acquisition of the activity also suggests an adaptive advantage for eudicots to acquire ß-GGM ß-galactosylation, and hence also suggests the disaccharide side chains are important for ß-GGM function.

Changes in volatile flavors during the fermentation of tomato (Solanum lycopersicum L.) juice and its storage stabilization.

Flavor is a crucial indicators of the quality of fermented tomato juice; however, there has been limited research in this area. Herein, headspace solid-phase microextraction gas chromatography-mass spectrometry was used to analyze the volatile metabolites at different stages during FTJ fermentation. 131 volatile organic compounds (VOCs) were identified, with alcohols, acids, and esters as the main compounds. The content of superoxide dismutase (SOD) and lycopene (LYC) had a positive correlation with methyl salicylate, ethyl acetate, and linalyl acetate. Subsequently, the storage stability of FTJ was evaluated at temperatures of 4 °C, 25 °C, and 37 °C over a period of 45 d, revealing that the quality of FTJ decreased with increasing storage temperature. The shelf life of FTJ under different storage conditions was determined using SOD activity and LYC content as quality indicators. The final shelf life was 47 d at 37 °C, 69 d at 25 °C, and 123 d at 4 °C.

RNA-protein interactions reveals the pivotal role of lncRNA1840 in tomato fruit maturation.

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.

Stabilization of fermented tomato (Solanum lycopersicum L.) juice by differently charged hydrocolloids.

This study investigated the impact of three different charged hydrocolloids, anionic polysaccharide (soluble soybean polysaccharide, SSPS), neutral polysaccharide (pullulan polysaccharide, PUL), and cationic polysaccharide (chitosan, CS), and their complexation on the stabilization efficiency of fermented tomato juice (FTJ). The effect of hydrocolloids on FTJ under different treatment conditions were comprehensively evaluated by determining the particle size distribution, zeta potential, rheological properties, Fourier transform infrared spectroscopy, surface tension, and LUMiSizer. The combined conditions suggest that PUL exhibits better storage stability than SSPS and CS when used individually. Compared with the use of the stabilizers, the combination of hydrocolloids had a greater impact on the storage stability of the FTJ, and the storage stability of the FTJ increased when 0.15% SSPS + 0.03% PUL + 0.15% CS was added. This study lays the groundwork for the development of stable fruit juice beverages.

Regulation of Anthocyanin Accumulation in Tomato Solanum lycopersicum L. by Exogenous Synthetic dsRNA Targeting Different Regions of SlTRY Gene.

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.

Rhizosphere microbiomes derived from vermicompost alter gene expression and regulatory pathways in tomato (Solanum lycopersicum, L.).

The gut microbiome of worms from composting facilities potentially harbors organisms that are beneficial to plant growth and development. In this experiment, we sought to examine the potential impacts of rhizosphere microbiomes derived from Eisenia fetida worm castings (i.e. vermicompost) on tomato (Solanum lycopersicum, L.) plant growth and physiology. Our experiment consisted of a greenhouse trial lasting 17 weeks total in which tomato plants were grown with one of three inoculant treatments: a microbial inoculant created from vermicompost (V), a microbial inoculant created from sterilized vermicompost (SV), and a no-compost control inoculant (C). We hypothesized that living microbiomes from the vermicompost inoculant treatment would enhance host plant growth and gene expression profiles compared to plants grown in sterile and control treatments. Our data showed that bacterial community composition was significantly altered in tomato rhizospheres, but fungal community composition was highly variable in each treatment. Plant phenotypes that were significantly enhanced in the vermicompost and sterile vermicompost treatments, compared to the control, included aboveground biomass and foliar δ15N nitrogen. RNA sequencing revealed distinct gene expression changes in the vermicompost treatment, including upregulation of nutrient transporter genes such as Solyc06g074995 (high affinity nitrate transporter), which exhibited a 250.2-fold increase in expression in the vermicompost treatment compared to both the sterile vermicompost and control treatments. The plant transcriptome data suggest that rhizosphere microbiomes derived from vermicompost can influence tomato gene expression and growth-related regulatory pathways, which highlights the value of RNA sequencing in uncovering molecular responses in plant microbiome studies.

Comparative histopathology of virulent and avirulent Meloidogyne javanica populations on susceptible and resistant tomato plants.

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'.

Biostimulants Enhance the Nutritional Quality of Soilless Greenhouse Tomatoes.

The application of biostimulants in vegetable cultivation has emerged as a promising approach to enhance the nutritional quality of crops, particularly in controlled environment agriculture and soilless culture systems. In this study, we employed a rigorous methodology, applying various biostimulants amino acids, Plant Growth-Promoting Rhizobacteria (PGPR), fulvic acid, chitosan, and vermicompost along with mineral fertilizers, both foliar and via the roots, to soilless greenhouse tomatoes during spring cultivation. The experiment, conducted in a coir pith medium using the 'Samyeli F1' tomato cultivar, demonstrated that plants treated with biostimulants performed better than control plants. Notable variations in nutritional components were observed across treatments. PGPR had the best effects on the physical properties of the tomato fruit, showing the highest fruit weight, fruit length, equatorial diameter, fruit volume, fruit skin elasticity, and fruit flesh hardness while maintaining high color parameters L, a, and b. PGPR and fulvic acid demonstrated significant enhancements in total phenolics and flavonoids, suggesting potential boosts in antioxidant properties. Amioacid and vermicompost notably elevated total soluble solids, indicating potential fruit sweetness and overall taste improvements. On the other hand, vermicompost stood out for its ability to elevate total phenolics and flavonoids while enhancing vitamin C content, indicating a comprehensive enhancement of nutritional quality. In addition, vermicompost had the most significant impact on plant growth parameters and total yield, achieving a 43% increase over the control with a total yield of 10.39 kg/m2. These findings underline the specific nutritional benefits of different biostimulants, offering valuable insights for optimizing tomato cultivation practices to yield produce with enhanced health-promoting properties.

SlBTB19 interacts with SlWRKY2 to suppress cold tolerance in tomato via the CBF pathway.

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.

Transcriptional reprogramming of tomato (Solanum lycopersicum L.) roots treated with humic acids and filter sterilized compost tea.

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.

Earthworm mucus contributes significantly to the accumulation of soil cadmium in tomato seedlings.

Whether earthworm mucus affects Cd transport behavior in soil-plant systems remains uncertain. Consequently, this study thoroughly assessed the impacts of earthworm mucus on plant growth and physiological responses, plant Cd accumulation, translocation, and distribution, as well as soil characteristics and Cd fractionation in a soil-plant (tomato seedling) system. Results demonstrated that the earthworm inoculation considerably enhanced plant Cd uptake and decreased plant Cd translocation, the effects of which were appreciably less significant than those of the earthworm mucus. This suggested that earthworm mucus may play a crucial role in the way earthworms influence plant Cd uptake and translocation. Moreover, the artificial mucus, which contained identical inorganic nitrogen contents to those in earthworm mucus, had no significant effect on plant Cd accumulation or translocation, implying that components other than inorganic nitrogen in the earthworm mucus may have contributed significantly to the overall effects of the mucus. Compared with the control, the earthworm mucus most substantially increased the root Cd content, the Cd accumulation amount of root and whole plant, and root Cd BCF by 93.7 %, 221.3 %, 72.2 %, and 93.7 %, respectively, while notably reducing the Cd TF by 48.2 %, which may be ascribed to the earthworm mucus's significant impacts on tomato seedling growth and physiological indicators, its considerable influences on the subcellular components and chemical species of root Cd, and its substantial effects on the soil characteristics and soil Cd fractionation, as revealed by correlation analysis. Redundancy analysis further suggested that the most prominent impacts of earthworm mucus may have been due to its considerable reduction of soil pH, improvement of soil DOC content, and enhancement of the exchangeable Cd fraction in soil. This work may help better understand how earthworm mucus influences the transport behavior of metals in soil-plant systems.

Identification and mapping of late blight resistance QTLs in the wild tomato accession PI 224710 (Solanum pimpinellifolium).

Late blight (LB), caused by oomycete Phytophthora infestans, is one of the most destructive diseases of the cultivated tomato, Solanum lycopersicum. Since new and aggressive clonal lineages of P. infestans, many of which overcoming formerly effective fungicides or host resistance genes, have continued to emerge, it is crucial to identify, characterize, and utilize new sources of host resistance in tomato breeding. A recent screening of tomato germplasm identified Solanum pimpinellifolium accession PI 224710 with very strong resistance to several current P. infestans clonal lineages. The present study aimed to identify and characterize QTLs associated with LB resistance in PI 224710. Disease screening of a large F2 population (n = 1721), derived from a cross between PI 224710 and LB-susceptible tomato breeding line Fla. 8059, followed by F3 progeny testing, resulted in the identification of 43 highly-resistant and 27 highly-susceptible F2 individuals. A selective genotyping approach, using 469 non-identical SNP markers, resulted in the construction of a genetic linkage map and identification of three LB-resistance QTLs on chromosomes 6, 9 and 10 of PI 224710. A comparison of the QTLs genomic locations with the tomato physical map resulted in the identification of several candidate genes, which might be underpinning the LB-resistance QTLs in PI 224710. The identified markers associated with the LB-resistance QTLs can be utilized in breeding programs to transfer resistance from PI 224710 into tomato breeding lines and hybrid cultivars via marker-assisted breeding; they also can be used to develop near-isogenic lines for fine mapping of the QTLs. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01498-1.

Microbiome transition mediated plant immune response to Alternaria solani (Ellis & Martin) Jones & Grout infection in tomato (Solanum lycopersicum L.).

Alternaria solani (Ellis & Martin) Jones & Grout, causing early blight infection in solanaceous crops, is a growing threat influencing sustainable crop production. Understanding the variation in the foliar microbiome, particularly the bacterial community during pathogenesis, can provide critical information on host-pathogen interactions, highlighting the host immune response during pathogen invasion. In the present study, early blight (EB) infection was artificially induced in tomato leaves, and the transition in the foliar bacterial community from healthy leaf tissue to infected leaves was analyzed. The 16s sequencing data revealed a significant shift in alpha and beta diversity, with infected leaf tissue exhibiting considerably lower bacterial abundance and diversity. Further interpretation at the genus level highlighted the possible role of the host immune system in recruiting higher nitrogen-fixing bacteria to resist the pathogen. The study, in addition to analyzing the foliar bacterial community transition during pathogenesis, has also shed light on the possible strategy employed by the host in recruiting selective nutrient-enriching microbes. Further application of this research in developing biocontrol agents with higher microbial host colonizing ability will be of tremendous benefit in achieving sustainable EB control measures.

Suprathreshold Water Spray Stimulus Enhances Plant Defenses against Biotic Stresses in Tomato.

Mechanical stimuli can affect plant growth, development, and defenses. The role of water spray stimulation, as a prevalent mechanical stimulus in the environment, in crop growth and defense cannot be overlooked. In this study, the effects of water spray on tomato plant growth and defense against the chewing herbivore Helicoverpa armigera and necrotrophic fungus Botrytis cinerea were investigated. Suprathreshold water spray stimulus (LS) was found to enhance tomato plant defenses against pests and pathogens while concurrently modifying plant architecture. The results of the phytohormone and chemical metabolite analysis revealed that LS improved the plant defense response via jasmonic acid (JA) signaling. LS significantly elevated the level of a pivotal defensive metabolite, chlorogenic acid, and reduced the emissions of volatile organic compounds (VOCs) from tomato plants, thereby defending against pest and pathogen attacks. The most obvious finding to emerge from this study is that LS enhances tomato plant defenses against biotic stresses, which will pave the way for further work on the application of mechanical stimuli for pest management.

Exploring the Antifungal Activity of Moroccan Bacterial and Fungal Isolates and a Strobilurin Fungicide in the Control of Cladosporium fulvum, the Causal Agent of Tomato Leaf Mold Disease.

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.

Photosynthetic Activities, Phytohormones, and Secondary Metabolites Induction in Plants by Prevailing Compost Residue.

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.

Herbivore-induced volatiles reduce the susceptibility of neighboring tomato plants to transmission of a whitefly-borne begomovirus.

Plant viruses exist in a broader ecological community, with key components include non-vector herbivores that can impact vector abundance, behavior, and virus transmission within shared host plants. However, little is known about the effects of non-vector herbivores infestation on the virus transmission by vector insects on the neighboring plants through inter-plant airborne chemicals. In this study, we investigated how volatiles emitted from tomato plants infested with the two-spotted spider mite (Tetranychus urticae) affect the infection of Tomato yellow leaf curl virus (TYLCV) transmitted by the whitefly (Bemisia tabaci) in the neighboring plants. Exposure of neighboring tomato plants to volatiles released from T. urticae-infested tomato plants reduced subsequent herbivory as well as TYLCV transmission and infection, and JA signaling pathway was essential for generation of the inter-plant defense signals. We also demonstrated that (E)-ß-Ocimene and MeSA were two volatiles induced by T. urticae that synergistically attenuated TYLCV transmission and infection in tomato. Thus, our findings suggest that plant-plant communication via volatiles likely represents a widespread defensive mechanism that substantially contributes to plant fitness. Understanding such phenomena may help us to predict the occurrence and epidemic of multiple herbivores and viruses in the agroecosystem, ultimately to manage pest and virus outbreaks.

Combined salt and low nitrate stress conditions lead to morphophysiological changes and tissue-specific transcriptome reprogramming in tomato.

Despite intense research towards the understanding of abiotic stress adaptation in tomato, the physiological adjustments and transcriptome modulation induced by combined salt and low nitrate (low N) conditions remain largely unknown. Here, three traditional tomato genotypes were grown under long-term single and combined stresses throughout a complete growth cycle. Physiological, molecular, and growth measurements showed extensive morphophysiological modifications under combined stress compared to the control, and single stress conditions, resulting in the highest penalty in yield and fruit size. The mRNA sequencing performed on both roots and leaves of genotype TRPO0040 indicated that the transcriptomic signature in leaves under combined stress conditions largely overlapped that of the low N treatment, whereas root transcriptomes were highly sensitive to salt stress. Differentially expressed genes were functionally interpreted using GO and KEGG enrichment analysis, which confirmed the stress and the tissue-specific changes. We also disclosed a set of genes underlying the specific response to combined conditions, including ribosome components and nitrate transporters, in leaves, and several genes involved in transport and response to stress in roots. Altogether, our results provide a comprehensive understanding of above- and below-ground physiological and molecular responses of tomato to salt stress and low N treatment, alone or in combination.

The Impact of Growing Area on the Expression of Fruit Traits Related to Sensory Perception in Two Tomato Cultivars.

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.