Project description:Drought stress can cause huge crop production losses. Drought resistance consists of complex traits, and is regulated by arrays of unclear networks at the molecular level. A stress-responsive NAC transcription factor gene SNAC1 has been reported for its function in the positive regulation of drought resistance in rice, and several downstream SNAC1 targets have been identified. However, a complete regulatory network mediated by SNAC1 in drought response remains unknown. In this study, we performed Chromatin immunoprecipitation sequencing (ChIP-Seq) and RNA-Seq of SNAC1-overexpression transgenic rice (SNAC1-OE) lines and wild-type under normal and moderate drought stress conditions, to identify all SNAC1 target genes at a genome-wide scale by RNA-Seq analyses. We detected 980 differentially expressed genes (DEGs) in the SNAC1-OE lines compared to the wild-type control under drought stress conditions. By ChIP-Seq analyses, we identified 4,339 SNAC1-binding genes under drought stress conditions (SNAC1BGDs). By combining the DEGs and SNAC1BGDs, we identified 93 SNAC1-targeted genes involved in drought responses (SNAC1TGDs). Most SNAC1TGDs are involved in transcriptional regulation, response to water loss, and other processes related to stress responses. Moreover, the major motifs in the SNAC1BGDs promoters include a NAC recognition sequence (NACRS) and an ABA responsive element (ABRE). SNAC1-OE lines are more sensitive to ABA than wild-type. SNAC1 can bind to the OsbZIP23 promoter, an important ABA signaling regulator, and positively regulate the expression of several ABA signaling genes.
Project description:Purpose: In this study we investigated the role of JASMONATE RESISTANT 1 (JAR1) and JAR1 mediated JA-Ile formation in drought stress tolerance in Arabidopsis thaliana. Methods: Global transcriptional changes in a newly generated over-expression line (JAR1-OE; 35S::JAR1-1-YFP)), a T-DNA insertion line in the JAR1 locus (jar1-11;SALK_034543), and wild-type Col-0 were investigated by RNA-seq analyses of rosette leaves from 32 day-old plant that were either well-watered (control) or not watered after day 18 (drought). Plants were grown on soil under long-day conditions Results: Under control conditions, using a stringent cut-off (DESeq, adjusted to FDR < 0.01 and LogFC ≥ 1), we found only four differentially expressed genes (DEGs) between jar1-11 and Col-0, all of them downregulated. By contrast, we found 339 DEGs between JAR1-OE and Col-0, of which 134 were downregulated and 205 were upregulated. A comparison of the RNA-seq data from Col-0 between control and drought conditions revealed 3401 DEGs, of which 2023 were down- and 1378 upregulated. By comparison, jar1-11 plants, which were most heavily affected by drought stress, showed a much higher number (6139 in total; 2616 up- and 3523 down-regulated) of DEGs, while the more drought-tolerant JAR1-OE line displayed a lower number (2025 in total; 971 up- and 1054 down-regulated) of DEGs. 2411 DEGs were found between Col-0 and jar1-11 under drought among which 966 genes showed a higher and 1445 genes a lower expression level in jar1-11. On the other hand, out of 998 DEGs found between Col-0 and JAR1-OE under drought, 737 genes showed a higher and 261 genes a lower expression level in JAR1-OE. Moreover, we found 391 DEGs counter-regulated between jar1-11 and JAR1-OE. Conclusion:RNA-seq analysis and additional experiments of plants under control and drought stress conditions provided insight into the molecular reprogramming caused by the alteration in JA-Ile content.
Project description:Plants have evolved a sophisticated defense system to survive under natural drought conditions. MicroRNAs (miRNA) are small noncoding RNAs that act as a post-transcriptional regulator in the environmental stress response and developmental process. Although many studies have reported the involvement of the miRNAs in drought response, molecular mechanisms by which miRNAs confer drought tolerance remain elusive. Here, we show that MIR171f, a member of MIR171 gene family, is mainly expressed in response to drought stress and regulate transcript levels of SCARECROW-LIKE6-I (SCL6-I) and SCL6-II. The SCL6 genes are known to be involved in shoot branching and flag leaf morphology. The MIR171f-overexpressing (MIR171f-OE) transgenic plants showed reduced drought symptoms as compared with non-transgenic (NT) control plants under both field drought and PEG-mediated dehydration stress conditions. Transcriptome analysis using the MIR171f-OE and mir171f-K/O mutants revealed that MIR171f regulates the expression of flavonoid biosynthesis genes, consequently leading to drought tolerance. Flavonoid biosynthesis genes were up-regulated in MIR171f-OE plants as compared with NT control plants under both normal and drought conditions. Together, our findings demonstrated that MIR171f plays an important role in plant drought-tolerance mechanism by regulating transcript levels of SCL6-I and SCL6-II.
Project description:Mesembryanthemum crystallinum (common ice plant) is one of the most important halophyte plants for plant stress biology research. In this study, we established an efficient Agrobacterium-mediated transformation method in ice plant and confirmed that ice plant can sustain gene overexpression for four weeks. Expression of a salt-induced transcription factor McHB7 (OE) reached the highest level at seven days after infiltration. Under salt and drought stresses, the growth of OE was better than wild type (WT), and the activities of redox enzymes and chlorophyll contents were higher in OE than the WT. Using proteomics, 475, 510 and 378 proteins were identified to be significantly changed in the OE lines under control, salt, and drought conditions, respectively. Most increased proteins were involved in various processes including Calvin cycle, citric acid cycle, glycolysis, and antioxidant pathways. Some were found to participate in ABA biosynthesis or response. Metabolomics revealed that many metabolites and phytohormones in OE were involved in plant growth and development. Also, ABA was increased in OE lines under control, salt, and drought conditions. Yeast one-hybrid analysis showed that McHB7 can bind to ERD and ABA-related motifs. And protein-protein interaction analysis discovered the candidate proteins that were responsive to stresses and hormones (e.g., ABA).
2024-05-21 | PXD033521 | Pride
Project description:Root transcriptome under drought condition
Project description:The growth and fruit quality of grapevine are widely affected by abnormal climatic conditions such as water deficit. But how grapevine responds to drought stress is still largely unknown. Here we found that VaNAC26, a member of NAC transcription factor family, was up-regulated dramatically during cold, drought and salinity treatments in Vitis amurensis, a cold and drought-hardiness wild Vitis species. Ectopic overexpression of VaNAC26 enhanced the drought and salt tolerances in transgenic Arabidopsis. Higher activities of antioxidant enzymes and the lower concentration of H2O2 and O2- were found in VaNAC26-OE lines than in wild type plants under drought stress. These results indicate that the reactive oxygen species (ROS) scavenging was enhanced by VaNAC26 in transgenic lines. Microarray based transcriptome analysis reveals that genes related to jasmonic acid (JA) synthesis and signaling were up-regulated in VaNAC26-OE lines under both normal and drought conditions. VaNAC26 showed a specific binding ability on NACRS motif, which was broadly existent in the promoter regions of up-regulated genes in transgenic lines. Endogenous JA content was found increased obviously in VaNAC26-OE-2/3 lines. Our data suggests that VaNAC26 responds to abiotic stresses and may enhance the drought tolerance by transcriptional regulation of JA synthesis in Arabidopsis.
Project description:This was a comparative transcriptome analysis by using high throughput sequencing. To assess the effects of drought stress and NF-Y transcription factors ZmNF-YA1 and ZmNF-YB16 on maize, leaves from wild-type (W22), zmnf-ya1 (m67) mutant, wild-type (B104) and ZmNF-YB16 overexpression (OE) plants grow under well-watered and drought stress conditions were collected and RNAseq was performed. We tracked the gene expression events of inbred maize lines W22 or B104 seedlings in response to drought stress to evaluate how drought stress affects the gene expression program in maize. At the same time, we analyzed the effects of drought stress on gene expression in zmnf-ya1 and ZmNF-YB16 OE plants to investigate whether and how ZmNF-YA1 and ZmNF-YB16 confer drought stress tolerance in maize. Maize plants were grown under well-watered conditions until the V4 stage (zmnf-ya1 and W22) or V9 stage (ZmNF-YB16 OE and B104), and then half of them were exposed to drought stress treatment. Water loss in the soil and the electrolyte leakage from leaf cells were used to assess drought stress in plants. Leaves from 3-4 plants were pooled for each sample, and two replicates were used. RNA was extracted from small strips of leaf lamina excised from the first fully expanded leaf of the plants.