Project description:Leaf senescence, the last step of leaf development which is important for plant’s fitness, proceeds with age but is modulated by various environmental stresses and hormones. Salt stress is one of the well-known environmental stresses that accelerate leaf senescence. However, the molecular mechanisms how the signal of salt stress is integrated into leaf senescence programs are still elusive. In this study, we characterized the function of an Arabidopsis APETALA 2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) family transcription factor, ERF34, in salt stress-induced leaf senescence. ERF34 was differentially expressed under leaf senescence-inducing conditions including age, dark, and high salt. ERF34 negatively regulated salt stress-induced leaf senescence as well as promoted salt stress tolerance at diverse developmental stages. Analysis of genome-wide targets of ERF34 revealed that the overexpression of ERF34 could alter salt-responsive gene expression. Moreover, ERF34 directly bound to the promoters of EARLY RESPONSIVE TO DEHYDRATION 10 and RESPONSE TO DESICCATION 29A and activated their expression. Our findings imply that ERF34 is a key regulator in the convergence of salt stress response with the regulatory programs of leaf senescence and is a potential candidate for crop improvement, particularly by enhancing salt stress tolerance.
Project description:this study analyzed photosynthetic and fluorescence parameters of pecan under hydroponic conditions to simulate salt stress. The results showed that as the duration of salt stress increased, there was a corresponding increase in the intercellular carbon dioxide concentration (Ci) of the leaves, and photosynthesis was inhibited. The response of pecan to salt stress was measured using iTRAQ and LC/MS non-targeted metabolomics technology.
Project description:Protein kinases (PKs) are involved in plant growth and stress responses, and constitute one of the largest superfamilies due to numerous gene duplications. However, limited PKs have been functionally described in pecan, an economically important nut tree. Here, the comprehensive identification, annotation and classification of the entire pecan kinome was reported. A total of 967 PK genes were identified from pecan genome, and further classified into 20 different groups and 121 subfamilies using the kinase domain sequences, which were verified by the phylogenetic analysis. The receptor-like kinase (RLK) group contained 565 members, which constituted the largest group. Gene duplication contributed to the expansion of pecan kinome, 169 duplication events including 285 PK genes were found, and Ka/Ks ratio revealed they experienced strong negative selection. GO functional analysis indicated majority PKs involved in molecular functions and biological processes. The RNA-Seq data of PK genes in pecan were further analyzed at subfamily level, and different PK subfamilies performed various expression patterns across different conditions or treatments, suggesting PK genes in pecan involved in multiple biological functions and stress responses. Taken together, this study provided insight into the expansion, evolution and function of pecan PKs. Our findings regarding expansion, expression and co-expression analyses could lay a good foundation for future research to understand the roles of pecan PKs, and find the key candidate genes more efficiently.
Project description:Our study identified long term salt stress treatment to induce symptoms similar to developmental senescence. In order to identify possible crosstalk components shared between developmental and salt-triggered senescence. We first obtained the expression profile of Arabidopsis leaves under the condition of salt-induced senescence (4 days) and then compared it with the transcriptome of developmental leaf senescence.
Project description:The aim of this study was to characterize the tissue tolerance mechanisms of rice under salt stress. Our preliminary experiment identified a japonica rice landrace Shuzenji-kokumai (SZK), which is considered to be tissue-tolerant because it can maintain better growth than salt-sensitive rice while having a high Na+ concentration in the shoots under salt stress. These mechanisms differ from those of most salt-tolerant rice varieties, which have low Na+ concentrations in the shoots. We compared the physiological and molecular characteristics of SZK with those of FL478, a salt-tolerant variety, and Kunishi, a salt-sensitive variety. Under salt stress conditions, SZK accumulated high levels of Na+ in roots, leaf sheaths, and leaf blades, which were almost as high as those in the salt-sensitive Kunishi. Simultaneously, SZK maintained better growth and physiological status, as determined by its higher dry weight, lower electrolyte leakage ratio, and lower malondialdehyde concentration. OsNHX1 and OsNHX2 were up-regulated in the leaf sheaths of SZK, suggesting that Na+ is compartmentalized in the vacuole to avoid Na+ toxicity. In contrast, FL478 showed up-regulation of OsHKT1;5 and OsSOS1 in the roots, which exclude Na+ from the shoots. RNA-seq analysis showed that 4623 and 1998 differentially expressed genes (DEGs) were detected in the leaf sheaths and leaf blades of SZK, respectively. Among them, the HSP (heat shock protein) gene expression was highly up-regulated only in SZK, indicating that SZK protects against the protein damage caused by Na+ toxicity. Our findings suggest that SZK has atypical survival mechanisms under salt-stress conditions. These mechanisms offer potential traits for improving salt tolerance in rice.
Project description:Study of gene expression under no salt condition from total leaf RNA and gene expression after five days of salt stress in 150mM NaCl from total leaf RNA of PcINO1 and OsINO1 introgressed IR-64 transgenic rice lines.
Project description:Rice seedlings at 3-leaf stage were used for expression analysis in control and salt stressed (incloudling salt treatment for 3, 24hrs and recovery from salt stress for 24hrs) samples. Samples of shoots and roots from biological replicates of both genotypes were generated and the expression profiles were determined using Phalanx Rice OneArray@ v1.
Project description:The JA deficient mutant (aoc) showed weaker symptoms than WT when both are exposed to salt. JAs signaling in WT, appeared then to impair salt tolerance and we were interested, through this transcriptomic approach, to highlight the JA-dependent component of the salt stress response that could explain the differential phenotype We report, for root and 2nd leaf, the compared transcriptomes of WT and aoc, before and at 3 different times (1 h, 6 h and 72 h) after salt exposure. The study reveals some key JA-regulated negative and positive effectors of salt stress tolerance in rice
2023-06-20 | GSE206706 | GEO
Project description:Transcriptome in response to drought stress in pecan