Project description:Transcriptional profiling of rice shootunder drought condition. Goal was to determine the effects of drought on changes in gene expression.
Project description:Comparative transcriptional profiling of two contrasting rice genotypes,IRAT109 (drought-resistant japonica cultivar) and ZS97 (drought-sensitive indica cultivar), under drought stress during the reproductive stage
Project description:The young panicles 2 cm length were used for expression analysis in well watered control and drought stressed treatment. The panicle samples from biological replicates of six rice varieties were obtained in three independent experiments. The expression profiles were generated using Affymetrix rice genome arrays.
Project description:Rice plants were exogenously sprayed with synthetic phenyl-urea cytokinin under drought stress. Leaf proteome was analyzed for the differential expression of proteins.
Project description:Transcription factors play a crucial regulatory role in plant drought stress responses. In this study, a novel drought stress related bZIP transcription factor, OsbZIP62, was identified in rice. This gene was selected from transcriptome analysis of several typical rice varieties with different drought tolerance. The expression of OsbZIP62 was obviously induced by drought, hydrogen peroxide, and abscisic acid (ABA) treatment. Overexpression of OsbZIP62-VP64 (OsbZIP62V) enhanced the drought tolerance and oxidative stress tolerance of transgenic rice, while the osbzip62 mutants showed the opposite phenotype. RNA-seq analysis showed that many stress-related genes (e.g. OsGL1, OsNAC10, and DSM2) were up-regulated in OsbZIP62V plants. OsbZIP62 could bind to the abscisic acid–responsive element (ABRE) and promoters of several putative target genes. Taken together, OsbZIP62 positively regulated rice drought tolerance through regulated the expression of genes associated with stress.
Project description:In this research, an array of 27,448 rice genes was used to elucidate gene expression in air-dried rice seedlings (lead and root) at various periods of treatment times. The analyses show that rice responds to drought stress mainly by down-regulating many biological processes including gene expression and regulation, protein phosphorylation, and cellular metabolism. Among strategies to actively adapt to drought, most significant are inducing protective molecules, which may be differentially regulated based on plant organs.
Project description:OsNAC6 is a stress responsive NAC transcription factor in rice known as a regulator for the transcriptional networks of the drought tolerance mechanisms. However, little is known about the associated molecular mechanisms for drought tolerance. Here, we identified OsNAC6-mediated root structural adaptation such as increased root number and root diameter that was sufficient to confer drought tolerance. Multiyear (5 years) drought field tests clearly demonstrated that OsNAC6 overexpression in roots produced higher grain yield under drought conditions. Genome-wide analyses revealed that OsNAC6 directly up-regulated 13 genes. Taken together, OsNAC6 is a valuable candidate for genetic engineering of drought-tolerant high-yielding crops.
Project description:We investigated the physiological and gene expression response of drought-tolerant (IR57311 and LC-93-4; subgroup indica) and drought-sensitive (Nipponbare and Taipai 309; subgroup japonica) rice (Oryza sativa) cultivars to 18 days of drought stress in climate chamber experiments. Rice plants were grown under water sufficient and water limiting conditions in three independent experiments in a controlled climate chamber with 12 h day length at 600 µE m-2 s-1; temperature was 26°C in the light and 22°C at night, with a relative humidity of 75% in the light and 70% at night. Leaf material for expression profiling analysis was harvested five hours after the beginning of the light period after 18 days of stress or control treatment. Normalization and statistical testing was performed using the R package limma (R 2.3.1, limma version 2.7.3; (Smyth, 2005)). The methods Robustspline for within array normalization and Quantile for between array normalization were applied. A linear model with the effects genotype, drought treatment, genotype x drought, dye was fitted to normalized data in limma that models the systemic variation in the data. Afterwards, for the comparisons of interest, moderated t-statistics that use an empirical Bayes method were calculated. Differentially expressed genes were identified using the decideTests function (method global, Benjamini & Hochberg fdr corrected p-value <0.05 in limma) Keywords: stress reponse
Project description:Drought stress response involves vigorous reprogramming of transcriptome while the mechanism modulating this process remains elusive. The role of 3D-genome in the regulation of rice development has recently been unveiled in rice, which exhibited characteristics distinct from that in mammals and other plants. However, the relationship between spatial chromosome organization and drought responsive gene reprogramming is still poorly understood. In this study, we identified H3K9ac as an efficient histone mark that response dynamically to drought stress in rice and re-constructed high-resolution 3D genome contact maps based on these sites under the normal, drought, and recovery conditions. We discovered significant decondensation of chromatin contacts with over 10000 chromatin loops lost upon drought stress treatment while the recovery of 3D genome was limited after 4-day’s re-watering. We identified dominate promoter-promoter interacting (PPI) loops under each condition and identified their significant correlations to altered gene expressions in response to the corresponding condition. Based on the relative contact intensities of the PPI connections, we characterized super-promoter regions that integrate closer connections of genes with more vigorous inductions to condition shifts. Especially, about 75% of the drought stress-dominate PPI loops were associated to the binding by a well-defined drought stress-responsive transcription factor, OsbZIP23. The mutation of OsbZIP23 led to the diffuse of over 80% DS-dominate PPI loops and impaired the expression of the connected genes. As a case study, we showed how OsbZIP23 binding to a super-promoter region can integrate the PPI loop formation and transcriptional activation of four function-vital dehydrin genes upon drought stress. Our results shed light on the mechanisms of 3D genome dynamic in response to water supply variations in rice and highlight the role of OsbZIP23 in the regulation of chromatin loop formation under drought stress.
Project description:Rice is highly sensitive to drought, and the effect of drought may vary with the different genotypes and development stages. Genome-wide gene expression profiling was used as the initial point to dissect molecular genetic mechanism of this complex trait and provide valuable information for the improvement of drought tolerance in rice. Affymetrix rice genome array containing 48,564 japonica and 1,260 indica sequences was used to analyze the gene expression pattern of rice exposed to drought stress. The transcriptome from leaf, root, and young panicle at three developmental stages was comparatively analyzed combined with bioinformatics exploring drought stress related cis-elements.