Project description:Abiotic stresses such as salinity are very important factors limiting rice growth and productivity around the world. Affymetrix rice genome array containing 48,564 japonica and 1,260 indica sequences was used to analyze the gene expression pattern of rice responsive to salinity stress, try to elucidate the difference of genome-wide gene expression profiling of two contrasting rice genotypes in response to salt stress and to discover the salinity related genes and gene interaction and networks. Under salinity condition, the number of differentially expressed genes (DEGs) in 177-103 was more than that in IR64, and most of up-regulated DEGs in 177-103 are response to stress. But in IR64, most of up-regulated DEGs are transcription related genes. The DEGs under salinity showed very strong tissue specificity, the number of DEGs in leaf was more than that in root. A lot of genes differentially expressed by exogenous ABA treatment under salinity condition, such as Leaf senescence protein, 1-deoxy-D-xylulose 5-phosphate synthase 2 precursor and Protein of unknown function DUF26 were induced by ABA and contributed to salinity tolerance.
Project description:We designed an array based on the release 7 of Michigan State University (MSU) rice genome annotation database (http://rice.plantbiology.msu.edu). The array was used for investigating the expression divergence and regulation between two contrasting rice genotypes under high salinity stress.
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:Abiotic stresses such as salinity are very important factors limiting rice growth and productivity around the world. Affymetrix rice genome array containing 48,564 japonica and 1,260 indica sequences was used to analyze the gene expression pattern of rice responsive to salinity stress, try to elucidate the difference of genome-wide gene expression profiling of two contrasting rice genotypes in response to salt stress and to discover the salinity related genes and gene interaction and networks. Under salinity condition, the number of differentially expressed genes (DEGs) in 177-103 was more than that in IR64, and most of up-regulated DEGs in 177-103 are response to stress. But in IR64, most of up-regulated DEGs are transcription related genes. The DEGs under salinity showed very strong tissue specificity, the number of DEGs in leaf was more than that in root. A lot of genes differentially expressed by exogenous ABA treatment under salinity condition, such as Leaf senescence protein, 1-deoxy-D-xylulose 5-phosphate synthase 2 precursor and Protein of unknown function DUF26 were induced by ABA and contributed to salinity tolerance. In this study, the gene expression patterns across two organs including leaves and roots at seedling stage were characterized under control, salinity, salinity+ABA treatments by using the Affymetrix rice microarray platform based on a salinity tolerant rice line derived from IR64.
Project description:Phosphate (Pi) deficiency severely affects crop yield. Modern high yielding rice genotypes are sensitive to Pi deficiency whereas traditional rice cultivars are naturally compatible to low Pi ecosystems. However, the underlying molecular mechanisms for low Pi tolerance in traditional genotypes remain largely elusive. To delineate the molecular mechanisms for low Pi tolerance, two contrasting rice genotypes - Dular (low Pi tolerant) and PB1 (low Pi sensitive) - have been selected. Comparative morphophysiological, global transcriptome and lipidome analyses of root and shoot tissues of both genotypes raised under Pi deficient and sufficient conditions revealed the potential low Pi tolerance mechanisms of traditional genotype. Most of the genes associated with enhanced internal Pi utilization (phospholipid remobilization) and modulation of root system architecture (RSA) are highly induced in traditional rice genotype, Dular. Higher reserve of phospholipid and greater accumulation of galactolipids under low Pi in Dular indicated its better internal Pi utilization. Furthermore, Dular also maintained better root growth than PB1 under low Pi resulting in larger root surface area due to increased lateral root density and root hair length. Genes involved in enhanced low Pi tolerance of traditional genotype can be exploited to improve the low Pi tolerance of modern high yielding rice cultivars.
Project description:A submergence tolerant indica rice cultivar FR13A, was also reported to withstand salt stress and proven in our experiments. The mechanism of tolerance is yet to be studied by forward genetics approach. However, it is known that salt stress tolerance is governed by several QTLs and not by a single gene. To understand the mechanism of such a complex mechanism of salt tolerance we selected, two indica rice genotypes namely, I) FR13A, a tolerant indica variety and ii) IR24, a susceptible genotype for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under constitutive and salt stress conditions at seedling stage. Keywords: Mechanism of salt tolerance
Project description:A submergence tolerant indica rice cultivar FR13A, was also reported to withstand salt stress and proven in our experiments. The mechanism of tolerance is yet to be studied by forward genetics approach. However, it is known that salt stress tolerance is governed by several QTLs and not by a single gene. To understand the mechanism of such a complex mechanism of salt tolerance we selected, two indica rice genotypes namely, I) FR13A, a tolerant indica variety and ii) IR24, a susceptible genotype for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under constitutive and salt stress conditions at seedling stage. Experiment Overall Design: We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice plant tissues during salt stress treatment. We used two contrasting rice genotypes (FR13A tolerant and IR24 susceptible) differing in salt stress response. Plants were grown in growth chambers and treated with 150 mM salt concentration at 14th DAS. Sampling was done in both constitutive and treated plants at 3 time points. Two replications of microarray experiments were carried out by hybridizing the RNA from tolerant samples against the susceptible lines on the same slide.
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:Over the years, many traditional rice varietites of India were sourced and studied owing to their ability to withstand abiotic pressures like excessive salinity in the soil and water. These cultivars growing in specific areas of the country represent a rich gene pool from where a deeper understanding of the processes underlying tolerance to abiotic stress can be gained. Indigenous varieties like Nonabokra and Pokkali are known salt tolerant varieties and are being studied in great detail. In the present study, we have analyzed the transcriptomes of the contrasting cultivars; Nonabokra (tolerant), Pokkali (tolerant) and IR29 (susceptible) in order to decipher the differences in their responses to salinity stress by utilizing microarray.