Project description:Chilling stress is a major abiotic stress that affects rice growth and development. Rice seedlings are quite sensitive to chilling stress and this harms global rice production. Comprehensive studies of the molecular mechanisms for response to low temperature are of fundamental importance to chilling tolerance improvement. The number of identified cold regulated genes (CORs) in rice is still very small. Circadian clock is an endogenous timer that enables plants to cope with forever changing surroundings including light–dark cycles imposed by the rotation of the planet. Previous studies have demonstrated that the circadian clock regulates stress tolerances in plants show circadian clock regulation of plant stress tolerances. However, little is known about coordination of the circadian clock in rice chilling tolerance. In this study, we investigated rice responses to chilling stress under conditions with natural light-dark cycles. We demonstrated that chilling stress occurring at nighttime significantly decreased chlorophyll content and photosynthesis efficiency in comparison with that occurring at daytime. Transcriptome analysis characterized novel CORs in indica rice, and suggested that circadian clock obviously interferes with cold effects on key genes in chlorophyll (Chl) biosynthesis pathway and photosynthesis-antenna proteins. Expression profiling revealed that chilling stress during different Zeitberger times (ZTs) at nighttime repressed the expression of those genes involved Chl biosynthesis and photosynthesis, whereas stress during ZTs at daytime increases their expression dramatically. Moreover, marker genes OsDREBs for chilling tolerance were regulated differentially by the chilling stress occurring at different ZTs. The phase and amplitude of oscillation curves of core clock component genes such as OsLHY and OsPRR1 are regulated by chilling stress, suggesting the role of chilling stress as an input signal to the rice circadian clock. Our work revealed impacts of circadian clock on chilling responses in rice, and proved that the effects on the fitness costs are varying with the time in a day when the chilling stress occurs.
Project description:Using the HiSeqTM 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS) rice Y58S and P64S (Peiâai 64S) were analyzed at the fertility sensitive stage under cold stress.These datas would be most beneficial for further studies investigating the molecular mechanisms of rice responses to cold stress.
Project description:Rice is one of the most important global food crops, and is also a model organism for cereal research 31 . Complete genome sequencing of rice, together with advances in transcriptomics and proteomics, has had a dramatic impact on plant growth and 5 breeding programs 32 . Genomic analysis of DNA methylation in rice has revealed methylation patterns associated with gene bodies and promoters, and the occurrence of high levels of DNA methylation in the centromeric domain 33 . A genome-wide investigation of acetylation in rice revealed that H3K9ac and H3K27ac are mainly enriched at transcription start sites associated with active transcription 34 . Furthermore, global proteome analysis has shown that phosphorylation and succinylation are involved in diverse cellular and metabolic processes 35, 36 . However, despite these considerable advances in our knowledge, additional large-scale analysis of the lysine acetylome in rice is expected to identify many more Kac sites and acetylated proteins in this improtant crop plant. In this study, affinity enrichment and high-resolution LC-MS/MS were used for large-scale analysis of the lysine acetylome in rice variety Nipponbare. In total, 1353 lysine acetylation sites were detected in 866 protein groups in rice seedlings. Proteomic analysis showed that Kac occurs in proteins involved in diverse biological processes with varied cellular functions and subcellular localization.
Project description:The rice gene SUB1A-1 confers flooding tolerance restricting shoot growth during submergence. Rice with SUB1A also show more rapid recovery after submergence ends, but mechanisms by which SUB1A improves recovery from submergence had not been examined. In this study, the transcriptome was sequenced at five time points over a 24 hour submergence recovery period in near-isogenic rice genotypes with and without SUB1A.
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:Iron toxicity is one of the most common mineral disorders affecting Oryza sativa production in flooded lowland fields. Efforts have been made to develop new rice varieties tolerant to Fe toxicity (+Fe). Oryza meridionalis is an endemic from Northern Australia and grows in regions with Fe rich soils, which may provide Fe tolerance genes and mechanisms that can be used for adaptive breeding. Aiming to understand tolerance mechanisms in rice, we screened a population of interspecific introgression lines (IL) from a cross between O. sativa and O. meridionalis for the identification of QTLs contributing to Fe excess tolerance. Six putative QTLs were identified. A line carrying one introgression from O. meridionalis on chromosome 9 associated with one QTL for leaf bronzing score was identified as tolerant in terms of lipid peroxidation and electrolyte leakage despite presenting very high shoot Fe concentrations. Further physiological, biochemical, ionomic and transcriptomic analyses showed that the IL tolerance could be partly explained by Fe partitioning between the leaf sheath and culm. After the in silico construction of an interspecific hybrid genome to map the sequences from transcriptomic analysis, we identified 47 and 27 genes from O. meridionalis up and down-regulated, respectively, by Fe treatment on the tolerant IL. Among possible genes associated with shoot-based tolerance, we identified metallothionein-like proteins, genes from glutathione S-transferase family and transporters from ABC and Major Facilitator Superfamily. This is the first work to demonstrate that introgressions of O. meridionalis in O. sativa genome confer increased tolerance to +Fe
Project description:IDS1 is a rice AP2-type transcription factor with transcritpional repression activity. To understand how IDS1 regulate rice salt tolerance, the ChIP-seq experiments were performed to identify IDS1 binding site in globle genomic level. The two-weeks-old rice seedlings were lysated and sonificated and IDS1-DNA complexes were immune precipated with myc-antibody and protein A beads. The purified DNA samples were used to construct sequencing libraries and sequenced with Illumina. The data were then analyzed with bio-informatic tools.