Project description:Rice reproductive development is highly sensitive to high temperature stress. In rice flowering occurs over a period of at least 5 days. Heat stress alters the global gene expression dynamics in panicle especially during pollen development, anthesis and grain filling. Some of the rice genotypes like Nagina 22 show better spikelet fertility and grain filling compared to high yielding and popular rice cultivars like IR 64. We carried out microarray analysis of 8 days heat stressed panicles of Nagina22, heat and drought tolerant aus rice cultivar and IR64, a heat susceptible indica genotype along with unstressed samples of Nagina22 and IR64 so as to understand the transcriptome dynamics in these two genotypes under heat stress and to identify the genes important for governing heat stress tolerance in rice.
Project description:We analyzed the transcriptome profiles for rice grain from heat-tolerant and -sensitive lines in response to high night temperatures at the early milky stage using the Illumina Sequencing method. On the 8th day after the labeled florets flowered, plants with the same label were transferred to chambers and maintained at a temperature of 38.0â±â0.5°C (treatment) or 25.0â±â0.5°C (control) for the dark period (10 h), and 26.0â±â0.5°C (both treatment and control) for the light period (14 h). Three biological replicates of the temperature treatments were grown under the same conditions. After 48 h of treatment, samples containing 45 grains with labels from the same region (middle to bottom part) of labelled ears were harvested, packed in aluminum foil, and flash-frozen in liquid nitrogen until further use. A total of 12 rice grain samples were harvested, i.e., controls (TC1, TC2 and TC3) and treatments (TT1, TT2 and TT3) of the three biological replicates of the heat-tolerant line, and controls (SC1, SC2 and SC3) and treatments (ST1, ST2 and ST3) of the three biological replicates of the heat-sensitive line.
Project description:Heat stress along with other abiotic stresses is one of the major factors affecting crop health and overall yield in a tropical country like India. Thus, there is an urgent need to understand the dynamics of heat responsiveness at the molecular as well as physiological level. Fortunately, India has a number of indigenous varieties that show tolerance to extremes in temperature during the scorching summer months. The cultivar Annapurna is a fast growing dwarf variety of rice that is heat tolerant while the most widely grown indica rice in South and Southeast Asia, IR64, is susceptible to high temperatures. These two cultivars present an excellent opportunity to study the differences in response to heat stress, and, thereby help in elucidating the genes involved in conferring tolerance to high temperature. The present study involves transcript profiling of the two cultivars, Annapurna (tolerant) and IR64 (susceptible) under both control and heat stressed conditions.
Project description:we utilized microRNA sequencing to identify differentially expressed miRNAs in rice heat-tolerant line and heat-sensitive line under high night temperature stress .
Project description:we utilized microRNA sequencing to identify differentially expressed miRNAs in rice heat-tolerant line and heat-sensitive line under high night temperature stress .
Project description:we utilized transcriptome sequencing to identify differentially expressed genes in rice heat-tolerant line and heat-sensitive line under high night temperature stress .
Project description:To comprehend the gene expression profile in rice panicle under high temperature, Agilent 4×44k rice oligo microarray experiments were carried out using rice panicle of post-meiosis at 0 min, 10min, 20 min, 60 min, and 2 hr after the treatment of 40 degree centigrade, and the differentially expressed genes at the time course were involved in binding, catalysis, stress response, and cellular process. The significantly expressed genes were mainly up-regulated. Among HR genes, the predominant transcription factor gene families were Hsf, NAC, AP2/ERF, WRKY, MYB, and C2H2. The MapMan analysis demonstrated that, under heat treatment, the HR genes were enriched in the pathways related to biotic stress, abiotic stress including heat and cold, and cell cycle and development, ubiquitin-proteasome , lipid and secondary metabolisms, which revealed the great importance of cross-talk and protein homeostasis in response to heat in rice panicle of post-meiosis.
Project description:Purpose: The goal of our study is to compare two different ecotypes of Oryza sativa L., PHS-susceptible rice trait and PHS-resistant rice trait under three different maturation stages in rice seed embryo with profile of miRNA-seq. Methods: Oryza sativa. L miRNA profiles of two different ecotypes with 3 different maturation stages of rice seed embryo were generated by NGS, in duplicate, following Illumina NGS workflow. Results: We found the differentially expressed microRNAs between PHS-susceptible rice trait and PHS-resistant rice trait according to the three different seed maturation stages. Target transcripts of differentially expressed microRNAs have been predicted via psRNATarget web server, and a part of those target genes are likely to be regulated by microRNAs, affecting overall responses to heat stress and the regulation of seed dormancy during maturation. Conclusions: Our study represents the analysis of rice seed small RNAs, specifically microRNAs, under two different ecotypes, three different seed maturation stages in rice seed embryo. Our results show that microRNAs are involved in response to heat stress and the regulation of seed dormancy. This study will provide a foundation for understanding dynamics of seed dormancy during the seed development and overcoming pre-harvest sprouting.
Project description:Purpose: The goal of our study is to compare two different ecotypes of Oryza sativa L., PHS-susceptible rice trait and PHS-resistant rice trait under three different maturation stages and two different tissues, embryo and endosperm of rice seeds with profile of RNA-seq. Methods: Oryza sativa. L mRNA profiles of two different ecotypes with 3 different maturation stages and 2 different tissues were generated by NGS, in duplicate, following Illumina NGS workflow. qRT–PCR validation was performed using SYBR Green assays. Results: We found the differentially expressed genes (DEGs) between PHS-susceptible rice trait and PHS-resistant rice trait according to the three different seed maturation stages. In DEGs, gene ontology (GO) analysis and Mapman analysis were performed, and we discovered genes related to plant hormones and heat stress, which are not yet reported. These genes were validated through qRT-PCR, and it is likely to be highly related to seed dormancy. Conclusions: Our study represents the analysis of rice seed transcriptomes under two different ecotypes, three different seed maturation stages and two different tissues (Embryo and endosperm). Our results show that seed dormancy is affected and regulated by a plant hormones and heat stress. This study might provide a foundation for understanding dynamics of seed dormancy during the seed development and overcoming pre-harvest sprouting.
Project description:In order to evaluate the genome differences and find the more tolerant cultivar, first eleven Malaysian rice cultivars namely, MR219, MR276, MR220, MR211, MR219-4, MR253, Q50, Q74, MR159, Masuri and MR263 were subjected under water deficit. Then, based on the morphological and physiological traits, the more drought-tolerant and -susceptible cultivars were screened and time-course gene expression profiling established by a comprehensive transcriptome database sequencing of the leaf RNA of tolerant rice. The current investigation provides pivotal data for understanding the rice drought tolerance mechanisms.