ERF proteins are plant-specific transcription factors that play significant roles in plant defense against various stresses. However, only little information regarding stress-related ERF genes is ...available in tomato (Solanum lycopersicum, Sl). In this study, a tomato ERF gene, SlERF84, was cloned and functionally characterized. The nucleus localization of SlERF84-sGFP was confirmed through a transient expression assay. Transactivation assays in yeast demonstrated that SlERF84 functions as a transcriptional activator. Real-time PCR analysis revealed that SlERF84 could be markedly induced by drought, salt and by several phytohormones (ABA, MeJA and ACC). Overexpression of SlERF84 in Arabidopsis endows transgenic plants with ABA hypersensitivity and enhanced tolerance to drought and salt stress. Histochemical staining assay showed that SlERF84 renders transgenic plants better ROS-scavenging capability. Pathogen inoculation assay revealed that SlERF84 might negatively modulate plant defense response to Pseudomonas syringae pv. tomato DC3000. Moreover, the transcript levels of pathogenesis-related genes AtPR1 and AtPR3 were compromised in transgenic Arabidopsis, as compared to that in Col-0 plants when inoculated with Pseudomonas syringae pv. tomato DC3000. These results suggest that SlERF84 functions as a stress-responsive transcription factor in differentially modulation of abiotic and biotic stress tolerance, and may have applications in the engineering of economically important crops.
•SlERF84 could be induced by various abiotic stresses and plant hormones.•SlERF84 functions as a transcriptional activator.•Overexpression of SlERF84 in Arabidopsis enhanced tolerance to drought and salt stress.•SlERF84 negatively modulate plant defense response to pathogen Pst DC3000.
Given the potential environmental and economic sustainability consequences of cover crop adoption, N fertilizer application, and residue management, this study focuses on the yield and financial ...effects of these on processing tomato production in Ontario, Canada. The study employs financial modeling using field data from a long-term cover crop experiment (oat, cereal rye, radish, and a radish-rye mixture) from 2010 to 2020. Averaged over six experimental years, compared to no cover (87 Mg ha−1) radish (99.6 Mg ha−1) and radish-rye mix (95.2 Mg ha−1) cover crops produce statistically significantly higher tomato yields as isolated practices, increasing farm net returns by $1120 ha−1 and $604 ha−1, respectively. When combined with N application, rye application additionally results in tomato yields statistically significantly higher than the base practice of no cover crop, zero N application and retained residue. Oat cover does not appear to have a statistically significant effect on tomato yields in this dataset. The application of N fertilizer results in statistically significantly higher tomato yield, increasing net returns by $882 ha−1, while residue management does not.
• Anthocyanin fruit (Aft) and atroviolacea (atv) were characterized in wild tomato and can enhance anthocyanin content in tomato fruit. However, the gene underlying the Aft locus and the mechanism by ...which Aft and atv act remain largely unknown.
• In this study, the Aft locus was fine-mapped to an approximately 145-kb interval on chromosome 10, excluding SlAN2 (Solyc10g086250), SlANT1 (Solyc10g086260) and SlANT1-like (Solyc10g086270), which have previously been suggested as candidates. Thus, the R2R3-MYB transcription factor SlAN2-like (Solyc10g086290) was considered the best candidate gene for Aft.
• The CRISPR/Cas9-mediated SlAN2-like mutants show a much lower accumulation of anthocyanins associated with the downregulation of multiple anthocyanin-related genes compared to the wild-type tomato, indicating that SlAN2-like is responsible for the Aft phenotype. The repressive function of SlMYBATV also was confirmed through the CRISPR/Cas9 approach. A yeast-two-hybrid assay revealed that SlMYBATV interacts with the bHLH protein SlJAF13. Furthermore, yeast-one-hybrid and dual-luciferase transient expression assays showed that Aft directly binds to the SlMYBATV promoter and activates its expression.
• The results herein provide candidate genes to enhance anthocyanin content in tomato fruit. This research also provides insight into a mechanism involving the Aft-SlMYBATV pathway that fine-tunes anthocyanin accumulation in tomato fruit.
•Exogenous Si application (1.2 mmol L−1) enhanced tomato fruit firmness by.•Si application inhibited cell wall enzyme activities.•Ethylene production was also reduced by Si application.•Exogenous Si ...treatment can improve tomato fruit quality and shelf-life.
This study investigated the effects of exogenous silicon (Si) treatment on cell wall metabolism in tomato fruits. The experiment was conducted with ‘Jinfan502’ tomato (Solanum lycopersicum L.) as the test material, which was cultivated in substrates with foliar sprays of the following different concentrations of Si treatments: 0 mmol·L−1 (CK), 0.6 mmol·L−1 (T1), 1.2 mmol·L−1 (T2), and 1.8 mmol·L−1 (T3). To study the effects of the treatment on the mature green, breaker, and red ripening stages of tomato fruit cell wall components, cell wall metabolism-related enzyme activities, textural properties, and the impact of ethylene production during the red ripening stage were assessed. The results showed that the cell wall components and textural properties of the T2 treatment were significantly higher than those of the CK treatment in the green mature, breaker, and red ripening stages. Among them, at the red ripening stage of fruiting, the content of cell wall components in the T2 treatment was significantly improved, and the contents of protopectin, cellulose, hemicellulose, and expansin were increased by 6.29 %, 10.04 %, 2.52 %, and 3.95 %, respectively, relative to the CK treatment; the firmness of the fruit was also significantly increased, by 13.23 %, compared with the CK treatment. Cell-wall-metabolism-related enzyme activity was significantly lower in the T2 treatment than in the CK treatment at the green mature, breaker, and red ripening stages. When Si (T2) was applied during the red ripening stage, the activities of cell wall metabolism-related enzymes were significantly inhibited; compared to the CK treatment, the activities of pectinase (PE), polygalacturonase (PG), pectin methylesterase (PME), β-galactosidase (β-Gal), lipoxygenase (LOX), pectin lyase (PL), and cellulase (CL) were reduced by 16.34 %, 19.37 %, 28.07 %, 10.73 %, 19.86 %, 8.47 %, and 6.53 %, respectively. Furthermore, the ethylene content of the red ripened fruits under the T2 treatment was significantly reduced by 21.59 % compared to the CK treatment. In addition, multiple sets of significant or extremely significant negative correlations existed among ethylene, cell wall components, and textural properties at red ripening stage. Finally, principal component analysis and hierarchical cluster analysis of cell-wall metabolism-related enzyme activities in the three stages of treatment with different Si concentrations showed that the models significantly separated the T2 treatment from the CK, T1, and T3 treatments. In conclusion, exogenous Si T2 treatment (1.2 mmol·L−1) had the greatest effect on delaying cell wall metabolism, which provides the theoretical and technical basis for the enhancement of storage and transport resistance in tomatoes.
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A tomato core collection consisting of 122 gene bank accessions, including landraces, old cultivars, and wild relatives, was explored for variation in several plant growth, yield and fruit quality ...traits. The resequenced accessions were also genotyped with respect to a number of mutations or variations in key genes known to underlie these traits. The yield-related traits fruit number and fruit weight were much higher in cultivated varieties when compared to wild accessions, while, in wild tomato accessions, Brix was higher than in cultivated varieties. Known mutations in fruit size and shape genes could well explain the fruit size variation, and fruit colour variation could be well explained by known mutations in key genes of the carotenoid and flavonoid pathway. The presence and phenotype of several plant architecture affecting mutations, such as self-pruning (sp), compound inflorescence (s), jointless-2 (j-2), and potato leaf (c) were also confirmed. This study provides valuable phenotypic information on important plant growth- and quality-related traits in this collection. The allelic distribution of known genes that underlie these traits provides insight into the role and importance of these genes in tomato domestication and breeding. This resource can be used to support (precision) breeding strategies for tomato crop improvement.
Background: Tomato brown rugose fruit virus (ToBRFV) has spread worldwide affecting tomato crop production in several countries. Although there are commercial ToBRFV-resistant tomato varieties; ...still, careful monitoring of its prevalence is necessary for establishing feasible epidemiological control programs. Since Sonora has a strategic geographic location for tomato cultivation and export, studies on the detection and prevention of ToBRFV outbreaks are pertinent as part of the actions to achieve the eradication of this virus. Objective: To determine the recent prevalence of ToBRFV in tomato-producing areas of the state of Sonora, Mexico in the period 2021-2022, using a combination of molecular and serological tools. Methodology: Samples of tomato leaves and fruits were collected from commercial greenhouses in different regions of Sonora from September 2021 to June 2022. Forty-four tomato leaves and 42 seed samples were analyzed for ToBRFV using reverse transcriptase-polymerase chain reaction and by direct detection of viral epitopes by immunochromatography. Results: 60% and 48% of the samples tested positive for ToBRFV by immunochromatography and RT-qPCR, respectively, showing an exact agreement regarding the samples’ origin. Implications: Future research may focus on genomic analysis of viral isolates that would provide clues of ToBRFV propagation speed and emergence of particular viral strains typical of the place of origin. Conclusion: The presence of ToBRFV in the state of Sonora, Mexico is limited to specific geographic sites, which suggests that local regulations and phytosanitary actions have worked to control the spread of the virus.
The scents of volatile organic compounds (VOCs) are an important component of ripe fleshy fruit attractiveness, yet their variation across closely related wild species is poorly understood. ...Phylogenetic patterns in these compounds and their biochemical pathways offer insight into the evolutionary drivers of fruit diversity, including whether scent can communicate an honest signal of nutrient content to animal dispersers. We assessed ripe fruit VOC content across the tomato clade (Solanum sect. Lycopersicon), with implications for crop improvement since these compounds are key components of tomato flavor.
We analyzed ripe fruit volatiles from 13 species of wild tomato grown under common garden conditions. Interspecific variation in 66 compounds and their biochemical pathways was assessed in 32 accessions, with an accession-level phylogeny accounting for relatedness.
Wild tomato species can be differentiated by their VOCs, with Solanum pennellii notably distinct. Phylogenetic conservatism exists to a limited extent. Major clade-wide patterns corresponded to divergence of the five colored-fruited species from the nine green-fruited species, particularly for nitrogen-containing compounds (higher in colored-fruited) and esters (higher in green-fruited), the latter appearing to signal a sugar reward.
We established a framework for fruit scent evolution studies in a crop wild relative system, showing that each species in the tomato clade has a unique VOC profile. Differences between color groups align with fruit syndromes that could be driven by selection from frugivores. The evolution of colored fruits was accompanied by changes in biochemical pathways underlying esters and nitrogen-containing compounds, volatiles important to tomato flavor. This article is protected by copyright. All rights reserved.
Summary
Carotenoids are vital phytonutrients widely recognised for their health benefits. Therefore, it is vital to thoroughly investigate the metabolic regulatory network underlying carotenoid ...biosynthesis and accumulation to open new leads towards improving their contents in vegetables and crops.
The outcome of our study defines SlWRKY35 as a positive regulator of carotenoid biosynthesis in tomato. SlWRKY35 can directly activate the expression of the 1‐deoxy‐d‐xylulose 5‐phosphate synthase (SlDXS1) gene to reprogramme metabolism towards the 2‐C‐methyl‐d‐erythritol 4‐phosphate (MEP) pathway, leading to enhanced carotenoid accumulation. We also show that the master regulator SlRIN directly regulates the expression of SlWRKY35 during tomato fruit ripening.
Compared with the SlLCYE overexpression lines, coexpression of SlWRKY35 and SlLCYE can further enhance lutein production in transgenic tomato fruit, indicating that SlWRKY35 represents a potential target towards designing innovative metabolic engineering strategies for carotenoid derivatives.
In addition to providing new insights into the metabolic regulatory network associated with tomato fruit ripening, our data define a new tool for improving fruit content in specific carotenoid compounds.
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