Project description:The footprint of tomato cultivation, a cool region crop that exhibits heat stress (HS) sensitivity, is increasing in the tropics/sub-tropics. Knowledge of novel regulatory hot spots from varieties growing in the Indian sub-continent climatic zones could be vital for developing HS-resilient crops. Comparative transcriptome-wide signatures of a tolerant (CLN1621L) and sensitive (CA4) cultivar pair shortlisted from a pool of varieties exhibiting variable thermo-sensitivity using physiological-, survival- and yield-related traits revealed redundant to cultivar-specific HS regulation. The antagonistically expressing genes encode enzymes and proteins that have roles in plant defence and abiotic stresses. Functional characterization of three antagonistic genes by overexpression and silencing established Solyc09g014280 (Acylsugar acyltransferase) and Solyc07g056570 (Notabilis) that are up-regulated in tolerant cultivar, as positive regulators of HS tolerance and Solyc03g020030 (Pin-II proteinase inhibitor), that are down-regulated in CLN1621L, as negative regulator of thermotolerance. Transcriptional assessment of promoters of these genes by SNPs in stress-responsive cis-elements and promoter swapping experiments in opposite cultivar background showed inherent cultivar-specific orchestration of transcription factors in regulating transcription. Moreover, overexpression of three ethylene response transcription factors (ERF.C1/F4/F5) also improved HS tolerance in tomato. This study identifies several novel HS tolerance genes and provides proof of their utility in tomato thermotolerance.
Project description:The tomato SlDREB2 transcription factor was overexpressed in cultivated tomato (Solanum lycopersicum) and transgenic plants tolerance to salinity was compared to that of wild-type plants.
Project description:The tomato SlWRKY3 transcription factor was overexpressed in cultivated tomato (Solanum lycopersicum)and transgenic plants transcriptome was compared to that of wild-type plants.
Project description:Texas tomato production is vulnerable to extreme heat in the spring-summer cropping period, which is exacerbated by the lack of superior genetic materials that can perform well in such environments. There is a dire need for selecting superior varieties that can adapt to warm environments and exhibit high yield stability under heat stress conditions. This research aimed at identifying heat-tolerant varieties under heat-stress conditions in controlled and open-field environments and was carried out in three stages. For the first experiment, 43 varieties were screened based on yield responses in natural open-field environment. From those, 18 varieties were chosen and exposed to control (greenhouse: 26/20 °C) and constant heat-stress (growth-chamber: 34/24 °C) conditions for three months. Measurements were done for chlorophyll fluorescence, chlorophyll content (SPAD), plant height, stem diameter and heat injury index (HII). The last experiment was conducted in an open field with a pool of varieties selected from the first and second experiments. Leaf gas exchange, leaf temperature, chlorophyll fluorescence, SPAD value, electrolyte leakage, heat injury index and yield were assessed. From the combined studies, we concluded that heat-tolerant genotypes selected by using chlorophyll fluorescence and HII in controlled heat-stress conditions also exhibited heat-tolerance in open-field environments. Electrolyte leakage and HII best distinguished tomato varieties in open-field environments as plants with low electrolyte leakage and HII had higher total yield. 'Heat Master,' 'New Girl,' 'HM-1823,' 'Rally,' 'Valley Girl,' 'Celebrity,' and 'Tribeca' were identified as high heat-tolerant varieties. Through trait correlation analysis we provide a better understanding of which traits could be useful for screening and breeding other heat-tolerant tomato varieties.
Project description:The tomato SlWRKY3 transcription factor was overexpressed in cultivated tomato (Solanum lycopersicum)and transgenic plants transcriptome was compared to that of wild-type plants. At least 4 plants were collected for RNA extraction. The aim of the experiment was to compare transcriptomes of 35::SlWRKY3 plants and wild-type plants grown together and on MS (Murashige and Skoog) medium in vitro for 4 weeks. A technical replicate (dye swap) was conducted.
Project description:Climate change is one of the biggest threats that human society currently needs to face. Heat waves associated with global warming negatively affect plant growth and development and will increase in intensity and frequency in the coming years. Tomato is one of the most produced and consumed fruit in the world but remarkable yield losses occur every year due to the sensitivity of many cultivars to heat stress. New insights into how tomato plants are responding to heat stress will contribute to the development of cultivars with high yields under harsh temperature conditions. In this study, the analysis of microsporogenesis and pollen germination rate of eleven tomato cultivars after exposure to a chronic heat stress revealed differences between genotypes. The transcriptome of floral buds at two developmental stages of five cultivars revealed common and specific molecular responses implemented by tomato cultivars to cope with chronic heat stress. These data provide valuable insights into the diversity of the genetic response of floral buds from different cultivars to heat stress and may contribute to the development of future climate resilient tomato varieties.
Project description:Transcriptome analysis of tomato fruits under heat stress revealed that most SlCRK genes were downregulated upon heat treatment. GO enrichment analysis of genes that were co-expressed with SlCRK members have identified various stress response related and proteasoma protein catabolic process related genes, which may be involved in heat stress signaling Overall, our results provide valuable information for further research on the roles of SlCRKs in response to abiotic stress, especially heat stress.
Project description:Climate change is a major concern for agricultural crops, and the selection of tolerant genotypes in response to abiotic stresses represents an important breeding strategy to reduce yield losses. In addition, the continuous development of new and more accurate high-throughput technologies for the analysis of DNA sequences is the key to improve biological understanding and application of biological knowledge. In the present work, 27 tomato genotypes already evaluated for their response under high temperature conditions were sequenced by using the ddRAD sequencing technology. The main goal was to provide genomic data useful for identifying candidate genes and variants to cope with current climate changes. Total genomic DNA was extracted from leaves and sequenced on the HiSeq2500 Illumina instrument. Raw reads of the dataset were processed using different bioinformatics tools to generate a Variant Calling Format (VCF) file. The availability of resources reporting polymorphisms among genomes of different genotypes provides a useful basis for studying tomato tolerance to current climate changes and can be used by researchers and breeders to investigate the molecular response mechanisms and develop new breeding programs, also aided by Marked Assisted Selection (MAS). The raw reads were deposited into SRA database (https://www.ncbi.nlm.nih.gov/sra/PRJNA1137563).
Project description:BackgroundHigh temperature is a major environmental stress that limits plant growth and agriculture productivity. Mitogen-activated protein kinases (MAPKs) are highly conserved serine and threonine protein kinases that participate in response to diverse environmental stresses in plants. A total of 16 putative SlMAPK genes are identified in tomato, and SlMAPK3 is one of the most extensively studied SlMAPKs. However, the role of SlMAPK3 in response to heat stress is not clearly understood in tomato plants. In this study, we performed functional analysis of SlMAPK3 for its possible role in response to heat stress.ResultsqRT-PCR analyses revealed that SlMAPK3 relative expression was depressed by heat stress. Here, wild-type (WT) tomato plants and CRISPR/Cas9-mediated slmapk3 mutant lines (L8 and L13) were used to investigate the function of SlMAPK3 in response to heat stress. Compared with WT plants, slmapk3 mutants exhibited less severe wilting and less membrane damage, showed lower reactive oxygen species (ROS) contents, and presented higher both activities and transcript levels of antioxidant enzymes, as well as elevated expressions of genes encoding heat stress transcription factors (HSFs) and heat shock proteins (HSPs).ConclusionsCRISPR/Cas9-mediated slmapk3 mutants exhibited more tolerance to heat stress than WT plants, suggesting that SlMAPK3 was a negative regulator of thermotolerance. Moreover, antioxidant enzymes and HSPs/HSFs genes expression were involved in SlMAPK3-mediated heat stress response in tomato plants.
Project description:We report the gene expression profiles of tomato seedlings and fruits treated with or without ethanol under heat stress conditions.