Project description:OsPAO5 mainly functions to oxidize spermine and produce H2O2,which finally affects mesocotyl elongation in rice. Meanwhile ethylene and polyamines synthesis crosstalk has been reported in competing the common substrate. To further confirm the relationship between H2O2 and ethylene in contributing to the mesocotyl length, we conducted a transcriptome comparison between pao5-1 vs NIP, ACC-treatment vs Mock (NIP) and H2O2-treatment vs Mock (NIP).
Project description:We aimed to identify putative H2O2-regulated miRNAs expressed in rice seedlings under oxidative stress by using a deep sequencing approach developed by Solexa (Illumina). Two small RNA libraries were constructed from H2O2-treated and control rice seedlings, and more than five million small RNA sequence reads were generated for each library. We identified seven H2O2-responsive miRNA families via expression profiling of the miRNAs based on a comparative miRNAomic analysis in combination with experimental validation. Furthermore, 32 miRNAs, 17 from known miRNA loci and 15 from novel miRNA loci, were also newly identified from the sequencing data. To the best of our knowledge, this is the first report of a systematic investigation of H2O2-regulated miRNAs and their targets in plants.
Project description:Green plants are more robust to hydrogen peroxide (H2O2) stress and contain high endogeneous H2O2 levels which is generated during photorespiration and photosynthesis. Therefore, exgeneous H2O2 application mostly impose oxidative stress. To reduce endogenous H2O2 background, we adopted a strategy which is to grow Arabidopsis seedlings in the dark to eliminate light-induced H2O2 production, thus to reduce the endogenous H2O2 level. Exogenous H2O2 was then applied to induce transcriptome changes. Global gene expression is studied and compared between samples collected under 7d dark, 7d H2O2 treatment under dark and 7d light conditions.
Project description:Green plants are more robust to hydrogen peroxide (H2O2) stress and contain high endogeneous H2O2 levels which is generated during photorespiration and photosynthesis. Therefore, exgeneous H2O2 application mostly impose oxidative stress. To reduce endogenous H2O2 background, we adopted a strategy which is to grow Arabidopsis seedlings in the dark to eliminate light-induced H2O2 production, thus to reduce the endogenous H2O2 level. Exogenous H2O2 was then applied to induce transcriptome changes. Global gene expression is studied and compared between samples collected under 7d dark, 7d H2O2 treatment under dark and 7d light conditions. We cultured seedlings in the dark to reduce endogenous H2O2. Three conditions were used for transcriptome profiling: dark grown (dark); dark grown with exogenous H2O2 treatment (H2O2); and light grown (light). Three types of conditions were used for Arabidopsis seedling culture: dark, dark with 5 mM H2O2 treatment and light. Each condition was performed with two biological replicates. The seedlings were harvested at 7 days old.
Project description:Drought stress is an adverse factor with deleterious effects on several aspects of rice growth. However, the mechanism underlying drought resistance in rice remains unclear. To understand the molecular mechanism of the drought response in rice, drought-sensitive CSSL (Chromosome Single-substitution Segment Line) PY6 was used to map QTLs of sensitive phenotypes and to reveal the impact of the QTLs on transcriptional profiling. The QTL dss-1 was mapped onto the short arm of chromosome 1 of rice. According to transcriptomic analysis, the identified differentially expressed genes (DEGs) exhibited a downregulated pattern and were mainly enriched in photosynthesis-related GO terms, indicating that photosynthesis was greatly inhibited under drought. Further, according to weighted gene coexpression network analysis (WGCNA), specific gene modules (designating a group of genes with a similar expression pattern) were strongly correlated with H2O2 (4 modules) and MDA (3 modules), respectively. Likewise, GO analysis revealed that the photosynthesis-related GO terms were consistently overrepresented in H2O2-correlated modules. Functional annotation of the differentially expressed hub genes (DEHGs) in the H2O2 and MDA-correlated modules revealed cross-talk between abiotic and biotic stress responses for these genes, which were annotated as encoding WRKYs and PR family proteins, were notably differentially expressed between PY6 and PR403. We speculated that drought-induced photosynthetic inhibition leads to H2O2 and MDA accumulation, which can then trigger the reprogramming of the rice transcriptome, including the hub genes involved in ROS scavenging, to prevent oxidative stress damage. Our results shed light on and provide deep insight into the drought resistance mechanism in rice.
Project description:We aimed to identify putative H2O2-regulated miRNAs expressed in rice seedlings under oxidative stress by using a deep sequencing approach developed by Solexa (Illumina). Two small RNA libraries were constructed from H2O2-treated and control rice seedlings, and more than five million small RNA sequence reads were generated for each library. We identified seven H2O2-responsive miRNA families via expression profiling of the miRNAs based on a comparative miRNAomic analysis in combination with experimental validation. Furthermore, 32 miRNAs, 17 from known miRNA loci and 15 from novel miRNA loci, were also newly identified from the sequencing data. To the best of our knowledge, this is the first report of a systematic investigation of H2O2-regulated miRNAs and their targets in plants. Examination of 2 different small RNA expression profilings in the control and H2O2 treated rice samples.
Project description:Glycinebetaine-induced water-stress tolerance in codA-expressing transgenic indica rice is associated with up-regulation of several stress responsive genes. Rice (Oryza sativa L.), a non-accumulator of glycinebetaine (GB), is highly susceptible to abiotic stress. Transgenic rice with chloroplast-targeted choline oxidase encoded by the codA gene from Arthrobacter globiformis has been evaluated for inheritance of transgene up to R5 generation and water-stress tolerance. During seedling, vegetative and reproductive stages, transgenic plants could maintain higher activity of photosystem II and they show better physiological performance, e.g. enhanced detoxification of reactive oxygen species compared to wild-type plants under water-stress. Survival rate and agronomic performance of transgenic plants is also better than wild-type following prolonged water-stress. Choline oxidase converts choline into glycinebetaine and H2O2 in a single step. It is possible that H2O2 /GB might activate stress response pathways and prepare transgenic plants to mitigate stress. To check this possibility, microarray-based transcriptome analysis of transgenic rice has been done. It unraveled altered expression of many genes involved in stress responses, signal transduction, gene regulation, hormone signaling and cellular metabolism. Overall, 165 genes show more than 2 folds up-regulation at P value <0.01 in transgenic rice. Out of these, at least 50 genes are known to be involved in plant stress response. Exogenous application of H2O2 or GB to wild-type plants also induces such genes. Our data show that metabolic engineering for GB is a promising strategy for introducing stress tolerance in crop plants and which could be imparted, in part, by H2O2- and/or GB-induced stress response genes.
Project description:Glycinebetaine-induced water-stress tolerance in codA-expressing transgenic indica rice is associated with up-regulation of several stress responsive genes. Rice (Oryza sativa L.), a non-accumulator of glycinebetaine (GB), is highly susceptible to abiotic stress. Transgenic rice with chloroplast-targeted choline oxidase encoded by the codA gene from Arthrobacter globiformis has been evaluated for inheritance of transgene up to R5 generation and water-stress tolerance. During seedling, vegetative and reproductive stages, transgenic plants could maintain higher activity of photosystem II and they show better physiological performance, e.g. enhanced detoxification of reactive oxygen species compared to wild-type plants under water-stress. Survival rate and agronomic performance of transgenic plants is also better than wild-type following prolonged water-stress. Choline oxidase converts choline into glycinebetaine and H2O2 in a single step. It is possible that H2O2 /GB might activate stress response pathways and prepare transgenic plants to mitigate stress. To check this possibility, microarray-based transcriptome analysis of transgenic rice has been done. It unraveled altered expression of many genes involved in stress responses, signal transduction, gene regulation, hormone signaling and cellular metabolism. Overall, 165 genes show more than 2 folds up-regulation at P value <0.01 in transgenic rice. Out of these, at least 50 genes are known to be involved in plant stress response. Exogenous application of H2O2 or GB to wild-type plants also induces such genes. Our data show that metabolic engineering for GB is a promising strategy for introducing stress tolerance in crop plants and which could be imparted, in part, by H2O2- and/or GB-induced stress response genes. Experiment Overall Design: Rice (Oryza sativa L.), transgenic plants expressing codA gene from Arthrobacter globiformis were compared with untransformed plants at seedling level
Project description:This study aimed to investigate transcriptomic changes in Cryptococcus neoformans mutants. We report transcriptome wide changes in the puf4∆ under basal growth conditions (30˚C, midlog, YPD). We report transcriptome remodeling following hydrogen peroxide (H2O2) treatment in wildtype (H99) and gcn4∆ cells.
Project description:Salinity tolerance is a complex trait and, despite many efforts to obtain rice plants resistant to salt, few results have been achieved since a deeper understanding of the tolerance mechanisms is still needed. We used imaging of photosynthetic parameters, ion analysis and transcriptomic approaches to unveil differences between two rice varieties differing in salt sensitivity. Moreover, we analysed H2O2 production in roots, using a fluorescent probe, and the ensuing gene regulation. Transcriptomic analyses conducted in tolerant plants supported the set-up of an adaptive program consisting of allocating sodium preferentially to roots, restricting it to the oldest leaves and activating regulatory mechanisms of photosynthesis in new leaves. As a consequence, plants resumed growth even under prolonged salt stress. By contrast, in the susceptible variety, RNA profiling unveiled a mis-targeted response, leading to senescence and cell death. In roots of tolerant plants, an increase in H2O2 was observed as early as 5 minutes after treatment. Consequently, the expression of genes involved in perception, signal transduction and response to salt were induced at earlier times when compared to susceptible plant roots. Our results demonstrate that a prompt H2O2 signalling in roots participates to a coordinated response resulting in adaptation instead of senescence in salt treated rice plants.