Project description:Plants show a high degree of developmental plasticity in response to external cues, including day length and environmental stress. Water scarcity in particular can interfere with photoperiodic flowering, resulting in the acceleration of the switch to reproductive growth in several species, a process called drought escape. However, other strategies are possible and drought stress can also delay flowering, albeit the underlying mechanisms have never been addressed at the molecular level. We investigated these interactions in rice, a short day species in which drought stress delays flowering. A protocol that allows the synchronization of drought with the floral transition was set up to profile the transcriptome of leaves subjected to stress under distinct photoperiods. We identified clusters of genes that responded to drought differently depending on day length. Exposure to drought stress under floral-inductive photoperiods strongly reduced transcription of EARLY HEADING DATE 1 (Ehd1), HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1), primary integrators of day length signals, providing a molecular connection between stress and the photoperiodic pathway. However, phenotypic and transcriptional analyses suggested that OsGIGANTEA (OsGI) does not integrate drought and photoperiodic signals as in Arabidopsis, highlighting molecular differences between between long and short day model species.
Project description:In order to identify new miRNAs, NAT-siRNAs and possibly abiotic-stress regulated small RNAs in rice, three small RNA libraries were constructed from control rice seedlings and seedlings exposed to drought or salt stress, and then subjected to pyrosequencing.
Project description:In order to identify new miRNAs, NAT-siRNAs and possibly abiotic-stress regulated small RNAs in rice, three small RNA libraries were constructed from control rice seedlings and seedlings exposed to drought or salt stress, and then subjected to pyrosequencing. Totally three sets of small RNAs, which were obtained under normal condition as well as salt and drought stress conditions
Project description:Climate change is affecting the unprecedented drought scenario and frequent occurrence of pathogen infection in rice. Simultaneous occurrence of these stresses could lead to more crop loss. Transcription response of genes involved in combined stress would provide relevant candidate gene to develop climate resilient rice. We report individual drought, Xoo infection and combined stress on rice. RNA Seq of contrasting genotypes BPT5204 and TN1 has revealed many candidate genes. A meta-analysis further filtered out some candidate genes which could be used for breeding programme. Several genes identified were already characterized by other groups for individual stress condition. However the genes involved in drought and pathogen infection could be further used for genetic manipulation studies in future.
Project description:Floral organs are extremely sensitive to stress during anthesis and lead to severe yield loss. Rice anthers and pollinated pistils of two cultivars with contrasting tolerance to heat and drought stress under variable conditions, including control, heat, combined heat and drought stress, were used to explore gene expression pattern in male and female reproductive organs during anthesis under control and stress conditions. More gene regulation was induced by combined drought and heat stress than heat in anthers of both cultivars. N22 showed less regulation under combined stress than Moroberekan. The overlap of regulated genes between two cultivars was rather low, indicated the distinct molecular stress responses. We used whole genome microarrays to explore gene expression pattern and molecular mechanisms in male and female reproductive organs during anthesis under control and stress conditions in two rice cultivars, sought to identify the key transcripts that play roles in inducing heat and drought tolerance during reproduction in rice.
Project description:Three rice major tissues, namely flag leaf, shoot and panicle, were involved in this study. Each tissue had two kinds stress treatment, drought and high salinity, in 3 different time courses. For drought treated samples, an additional water recovery was applied. Each experiment had three replicates. Keywords: Comparison of gene expression in three tissues with stress treatment and without treatment To globally elucidate potential genes involved in drought and high-salinity stresses responses in rice, an oligomer microarray covering 37,132 genes including cDNA or EST supported and putative genes was applied to study the expression profiling of shoot, flag leaf, and panicle under drought or high-salinity treatment. Three rice major tissues, namely flag leaf, shoot and panicle, were involved in this study. Each tissue had two kinds stress treatment, drought and high salinity, in 3 different time courses. For drought treated samples, an additional water recovery was applied. Each experiment had three replicates.
Project description:Plants evolved several acquired tolerance traits for drought stress adaptation to maintain the cellular homeostasis. The combination of constitutive and acquired traits governs drought tolerance, which is crucial for maintaining crop productivity under drought. Drought affects protein synthesis, to uncover the translational landscape with response to drought stress in rice, polysome bound mRNA sequencing at anthesis stage in resistant APO and sensitive IR64 genotypes were performed. Our results demonstrate that drought tolerant genotype maintains higher transcripts bound to poly-ribosomes which facilitate higher protien synthesis which impacted on photosynthesis, spikelet fertility, seed filing and yield under drought stress. We identified many novel LncRNAs and relevant genes associated with translation which can play important role in manitaing grain protein content with drought tolerance.
Project description:Three rice major tissues, namely flag leaf, shoot and panicle, were involved in this study. Each tissue had two kinds stress treatment, drought and high salinity, in 3 different time courses. For drought treated samples, an additional water recovery was applied. Each experiment had three replicates. Keywords: Comparison of gene expression in three tissues with stress treatment and without treatment
Project description:A great majority of plants synchronize flowering with day length. In rice, the most important environmental cue that triggers flowering is the photoperiod. Here, we show that the s73 mutant, identified in a gamma irradiated Bahia collection, displays early flowering and photoperiodic insensitivity due to a null mutation in the SE5 gene, which encodes an enzyme implicated in phytochrome chromophore biosynthesis. s73 mutant plants showed a number of alterations in the characteristic diurnal expression patterns of master genes involved in photoperiodic control of flowering, resulting in up-regulation of Hd3a, the most important floral integrator. Ehd1, an additional rice floral activator, was also highly expressed in the s73 mutant, suggesting that SE5 represses Ehd1 in wild-type plants. Silencing of Ehd1 in both Bahia and s73 backgrounds implies that SE5 regulates Ehd1 expression. The data also indicate that SE5 confers photoperiodic sensitivity through regulation of Hd1. These results provide direct evidence that phytochromes inhibit flowering affecting both Hd1 and Ehd1 flowering pathways.
Project description:Rice is a critically important food source but yields worldwide are vulnerable to periods of drought. We exposed eight genotypes of upland and lowland rice (Oryza sativa L. ssp. japonica and indica) to drought stress at the late vegetative stage and harvested leaves for protein extraction and subsequent label-free shotgun proteomics. Gene ontology analysis revealed some differentially expressed proteins were induced by drought in all eight genotypes; we speculate that these play a universal role in drought tolerance. However, some highly genotype-specific patterns of response to drought suggest that some mechanisms of metabolic reprogramming are not universal. Such proteins had largely uncharacterized functions, making them biomarker candidates for drought tolerance screens.