Project description:Investigation of whole genome gene expression levels of plants with altered GEM mRNA levels, with and without ABA treatment (2 hours).
Project description:To compare the genome-wide transcriptional effect of ABA and iCB in tomato plants, we performed RNA-seq analysis of mock-, 10 uM ABA- or 10 uM iCB-treated plants. Differential gene expression analysis between mock- and ABA-treated or iCB-treated seedlings was done with DESeq2 and genes with an absolute value of log2 fold change (log2FC) > 1 or (log2FC) < -1 and p-adjusted value (padj) < 0.05 were selected. iCB upregulated and downregulated genes represent almost all the ABA-responsive genes, which reflects the activation of PYL1-like and PYL4-like and PYL8-like ABA receptors in tomato seedlings.
Project description:Mannitol is a putative osmoprotectant contributing to salt tolerance in several species. Arabidopsis plants transformed with the mannose-6-phosphate reductase (M6PR) gene from celery were dramatically more salt tolerant (at 100 mM NaCl) as exhibited by reduced salt injury, less inhibition of vegetative growth, and increased seed production relative to the wild type (WT). When treated with 200 mM NaCl, transformants produced no seeds, but did bolt, and exhibited less chlorosis/necrosis and greater survival and dry weights than the WT. Without salt there were no M6PR effects on growth or phenotype, but expression levels of 2272 genes were altered. Many fewer differences (1039) were observed between M6PR and WT plants in the presence of salt, suggesting that M6PR pre-conditioned the plants to stress. Previous work suggested that mannitol is an osmoprotectant, but mannitol levels are invariably quite low, perhaps inadequate for osmoprotectant effects. In this study, transcriptome analysis reveals that the M6PR transgene activated the downstream abscisic acid (ABA) pathway by up-regulation of ABA receptor genes (PYL4, PYL5, and PYL6) and down-regulation of protein phosphatase 2C genes (ABI1 and ABI2). In the M6PR transgenic lines there were also increases in transcripts related to redox and cell wall-strengthening pathways. These data indicate that mannitol-enhanced stress tolerance is due at least in part to increased expression of a variety of stress-inducible genes.
Project description:Although abscisic acid (ABA) and gibberellins (GAs) play pivotal roles in many physiological processes in plants, their interaction in the control of leaf growth remains elusive. In this study, genetic analyses of ABA and GA interplay in leaf growth were performed in Arabidopsis thaliana. The results indicate that for ABA and GA interaction, leaf growth of both the aba2/ga20ox1 and aba2/GA20OX1-OE plants exhibits partially additive effects but is similar to the aba2 mutant. Consistent with this result, transcriptome analysis suggests that a substantial proportion (45-65%) of the gene expression profile of aba2/ga20ox1 and aba2/GA20OX1-OE plants overlaps and shares a similar pattern to the aba2 mutant. Thus, these data support that ABA deficiency dominates leaf growth regardless of GA levels. Moreover, gene ontology (GO) analysis indicates gene enrichment in the categories of hormone response, developmental and metabolic processes, and cell wall organization in these three genotypes. Leaf developmental genes are also involved in ABA-GA interaction. Collectively, these data support that the genetic relationship of ABA and GA interaction involves multiple coordinated pathways rather than a simple linear pathway in the regulation of leaf growth. To better understand the molecular basis of ABA and GA interaction, transcriptome analysis was performed among the genotypes used in this study.
Project description:Using a transgenic line expressing HA-tagged ATAF1 uncovered >400 ChIP-seq peaks in ATAF1-HA plants compared to Col-0 wild-type plants. Only a small sub-set of the candidate peaks could be verified using ChIP-qpcr or EMSA. Among the verified peaks we uncovered the key ABA biosynthetic gene NCED3 as a target of ATAF1
