Transcriptomic analysis reveals the gene regulatory networks involved in leaf and root response to osmotic stress in tomato
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ABSTRACT: We performed a transcriptomic analysis on two tomato genotypes, M82 and Tondo, in response to a PEG-mediated osmotic treatment, mimicking water stress. The analysis was conducted separately on leaves and roots to characterize the specific response of these two organs. A total of 6,267 differentially expressed transcripts related to osmotic stress response was detected. The construction of gene co-expression networks defined the metabolic and signaling pathways of the common and specific responses of leaf and root. The common response was characterized by ABA-dependent and ABA-independent signaling pathways, and by the interconnection between ABA and JA signaling. The root specific response concerned genes involved in cell wall metabolism and remodeling, whereas the leaf specific response was principally related to leaf senescence and ethylene signaling. The transcription factors representing the hubs of these regulatory networks were identified. Some of them have not yet characterized and can represent novel candidates for tolerance. Finally, several genes showing a genotype-specific expression regulation in response to the treatment were detected. These genes may be involved in the different sensitivity to the osmotic treatment of the two tomato genotypes. In conclusion, this work shed new light on the regulatory networks occurring in tomato leaf and root under osmotic stress and set the base for an in-depth characterization of novel stress-related genes, that may represent potential candidates for improving tolerance to water stress in tomato.
Project description:SlJMJ4 is a positive regulator of leaf senescence in tomato and mediates ABA-induced leaf senescence by activating the transcription of many genes related to ABA synthesis and signaling, and transcription regulation via removal of their H3K27me3 levels.
Project description:The signaling pathway of the phytohormone abscisic acid (ABA) regulates responses towards abiotic stress such as drought and high osmotic conditions. The multitude of functionally redundant components involved in ABA signaling, poses a major challenge for elucidating the largely unresolved response selectivity. We decided rebuilding single linear ABA signaling pathways in yeast for combinatoric permutation of ABA receptors and coreceptors, as well as the response-mediating SnRK2 protein kinases and their targeted transcription factors to drive luciferase expression in a heterologous host. We show that SnRK2s differ in the regulation by ABA receptor complexes, affect ABA responsiveness of the pathway, and differ in their transactivation activity but have similar preferences for ABA-responsive transcription factors. SnRK2s thought to act ABA-independently and known to be activated under osmotic stress in plants were regulated by ABA receptor complexes in yeast and competed with ABA receptor components in an ABA-dependent manner in plant tissue. The study reveals the suitability of the yeast system for analysis of ABA signaling factors and allowing the future dissection of ligand-receptor specificities in a functional response pathway. The analysis provides new insights into SnRK2 regulation indicating that four SnRK2 members of the osmotic stress response are tightly embedded into the ABA signaling pathway.
Project description:To identifiy osmotic stress responsive smRNAs, we used a deep-sequencing technique to profile small RNA populations in leaf and root tissues of plants under high osmotic stress and control conditions.
Project description:Results: In this study, the ears at the V9 stage, kernels and ear leaf at the 5DAP (days after pollination) stage of maize were used for morphological, physiological and comparative transcriptomics analysis to understand the different features of “sink” or “source” organs and the effects on kernel yield under drought stress conditions. The ABA-, NAC-mediate signaling pathway, osmotic protective substance synthesis and protein folding response were identified as common drought stress response in the three organs. Tissue-specific drought stress responses and the regulators were identified, they were highly correlated with growth, physiological adaptation and yield loss under drought stress. For ears, drought stress inhibited ear elongation, led to the abnormal differentiation of the paired spikelet, and auxin signaling involved in the regulation of cell division and growth and primordium development changes. In the kernels, reduced kernel size caused by drought stress was observed, and the obvious differences of auxin, BR and cytokine signaling transduction appeared, which indicated the modification in carbohydrate metabolism, cell differentiation and growth retardation. For the ear leaf, dramatically and synergistically reduced the expression of photosynthesis genes were observed when suffered from drought stress, the ABA- and NAC- mediate signaling pathway played important roles in the regulation of photosynthesis. Conclusions: Transcriptomic changes caused by drought were highly correlated with developmental and physiological adaptation, which was closely related to the final yield of maize, and a sketch of tissue- and developmental stage-specific responses to drought stress in maize was drafted.
Project description:Abscisic acid (ABA) determines mycorrhiza functionality and arbuscule development. Transcriptome analysis in response to different mycorrhization status according to the ABA concentration in the root was performed to identify genes that may play a role in arbuscule functionality. Tomato Affymetrix GeneChip (around 10,000 probes) allowed us to detect and compare the transcriptional root profiling of tomato (Solanum lycopersicum) wild-type and ABA-deficient sitiens plants colonized by the arbuscular mycorrhizal fungus Glomus intraradices. <br><br>
Project description:Sl2183 is an updated version of the previous tomato metabolic model (iHY3410), with additional reactions and metabolites, IDs converted into the BiGG nomenclature and biomass reactions for leaf, stem and root, allowing to generate a multi-organ model (see Gerlin et al., Plant Physiol. for additional information).
Project description:Hyperosmotic stress caused by drought and salinity is a significant environmental threat that limits plant growth and agricultural productivity. Osmotic stress induces diverse responses in plants including Ca2+ signaling, accumulation of the stress hormone abscisic acid (ABA), reprogramming of gene expression, and altering growth. Despite intensive investigation, no global regulators of all of these responses have been identified. Here, we show that the Ca2+-responsive phospholipid binding BONZAI (BON) proteins are critical for all of these osmotic stress responses. A Ca2+-imaging-based forward genetic screen identified a loss-of-function bon1 mutant with a reduced cytosolic Ca2+ signal in response to hyperosmotic stress. The loss-of-function mutants of the BON1 gene family, bon1bon2bon3, are impaired in the induction of gene expression and ABA accumulation in response to osmotic stress. In addition, the bon mutants are hypersensitive to osmotic stress in growth inhibition. BON genes have been shown to negatively regulate plant immune responses mediated by intracellular immune receptor NLR genes including SNC1. We found that the defects of the bon mutants in osmotic stress responses were suppressed by mutations in the NLR gene SNC1 or the immunity regulator PAD4. Our findings indicate that NLR signaling represses osmotic stress responses and that BON proteins suppress NLR signaling to enable global osmotic stress responses in plants.
Project description:The signaling pathway of the phytohormone abscisic acid (ABA) regulates responses towards abiotic stress such as drought and high osmotic conditions. The multitude of functionally redundant components involved in ABA signaling, poses a major challenge for elucidating the largely unresolved response selectivity. We decided rebuilding single linear ABA signaling pathways in yeast for combinatoric permutation of ABA receptors and coreceptors, as well as the response-mediating SnRK2 protein kinases and their targeted transcription factors to drive luciferase expression in a heterologous host. We show that SnRK2s differ in the regulation by ABA receptor complexes, affect ABA responsiveness of the pathway, and differ in their transactivation activity but have similar preferences for ABA-responsive transcription factors. SnRK2s thought to act ABA-independently and known to be activated under osmotic stress in plants were regulated by ABA receptor complexes in yeast and competed with ABA receptor components in an ABA-dependent manner in plant tissue. The study reveals the suitability of the yeast system for analysis of ABA signaling factors and allowing the future dissection of ligand-receptor specificities in a functional response pathway. The analysis provides new insights into SnRK2 regulation indicating that four SnRK2 members of the osmotic stress response are tightly embedded into the ABA signaling pathway.
Project description:Abiotic stresses such as salinity are very important factors limiting rice growth and productivity around the world. Affymetrix rice genome array containing 48,564 japonica and 1,260 indica sequences was used to analyze the gene expression pattern of rice responsive to salinity stress, try to elucidate the difference of genome-wide gene expression profiling of two contrasting rice genotypes in response to salt stress and to discover the salinity related genes and gene interaction and networks. Under salinity condition, the number of differentially expressed genes (DEGs) in 177-103 was more than that in IR64, and most of up-regulated DEGs in 177-103 are response to stress. But in IR64, most of up-regulated DEGs are transcription related genes. The DEGs under salinity showed very strong tissue specificity, the number of DEGs in leaf was more than that in root. A lot of genes differentially expressed by exogenous ABA treatment under salinity condition, such as Leaf senescence protein, 1-deoxy-D-xylulose 5-phosphate synthase 2 precursor and Protein of unknown function DUF26 were induced by ABA and contributed to salinity tolerance.