Project description:The aim of this study was to minimize the number of candidate genes responsible for salt tolerance between a pair of rice varieties (CSR27 and MI48) with contrasting level of salt tolerance by bulked segregant analysis of their recombinant inbred lines. Microarray analysis of RNA extracted from the tolerant and susceptible parents without and with stress showed 798 and 2407 differentially expressed genes, respectively. The number of differentially expressed genes was drastically reduced to 70 and 30, by pooling the RNAs from ten extreme tolerant and ten extreme susceptible RILs due to normalization of irrelevant differentially expressed genes between the parents.
Project description:The aim of this study was to minimize the number of candidate genes responsible for salt tolerance between a pair of rice varieties (CSR27 and MI48) with contrasting level of salt tolerance by bulked segregant analysis of their recombinant inbred lines. Microarray analysis of RNA extracted from the tolerant and susceptible parents without and with stress showed 798 and 2407 differentially expressed genes, respectively. The number of differentially expressed genes was drastically reduced to 70 and 30, by pooling the RNAs from ten extreme tolerant and ten extreme susceptible RILs due to normalization of irrelevant differentially expressed genes between the parents. RNA from CSR27, MI48, tolerant bulk and susceptible bulk grown under control and salt stress conditions were analysed in two different biological replications (A and B) making total sixteen samples
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.
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:Rice seedlings at 3-leaf stage were used for expression analysis in control and salt stressed (incloudling salt treatment for 3, 24hrs and recovery from cold stress for 24hrs) samples. Samples of shoots and roots from biological replicates of both genotypes were generated and the expression profiles were determined using Phalanx Rice OneArrayï¼ v1. Control and treated biological replicates of salt-tolerant cultivar TNG67 (japonica) and salt-sensitive cultivar TCN1 (indica) were analyzed
Project description:We advance a three gene model of arsenate tolerance in rice based on testing root growth of 108 recombinant inbred lines (RILs) of the Bala x Azucena population. Marker genotype at 3 loci determined arsenate tolerance in 99% of RILs tested. Interestingly, plants must inherit 2, but any two alleles from the tolerant parent (Bala) to have the tolerant phenotype. Challenging the Affymetrix GeneChip Rice Genome array with Azucena and Bala RNA isolated from control and arsenate treated plants revealed 592 genes 2 fold-upregulated by arsenate and 696 downregulated. The array data was also used to identify which genes are expressed within the three target loci. We used microarrays to detail the gene expression at three locations in the rice genome termed AsTol6.1, AsTol6.2 and AsTol10 in response to 1ppm arsenate. The data was also used to study the global gene expression of the two varieties of rice, Azucena and Bala, in the presence of 1ppm arsenate. Keywords: Hydroponics, 0 and 1ppm sodium arsenate, Rice varieties Azucena and Bala
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:To investigate the salt and waterlogging mechanism of barley, we chose salt and waterlogging sensitive and tolerant varieties as subjects. We then performed gene expression profiling analysis using data obtained from RNA-seq of two varieties at two three points.
Project description:The aim of this study was to characterize the tissue tolerance mechanisms of rice under salt stress. Our preliminary experiment identified a japonica rice landrace Shuzenji-kokumai (SZK), which is considered to be tissue-tolerant because it can maintain better growth than salt-sensitive rice while having a high Na+ concentration in the shoots under salt stress. These mechanisms differ from those of most salt-tolerant rice varieties, which have low Na+ concentrations in the shoots. We compared the physiological and molecular characteristics of SZK with those of FL478, a salt-tolerant variety, and Kunishi, a salt-sensitive variety. Under salt stress conditions, SZK accumulated high levels of Na+ in roots, leaf sheaths, and leaf blades, which were almost as high as those in the salt-sensitive Kunishi. Simultaneously, SZK maintained better growth and physiological status, as determined by its higher dry weight, lower electrolyte leakage ratio, and lower malondialdehyde concentration. OsNHX1 and OsNHX2 were up-regulated in the leaf sheaths of SZK, suggesting that Na+ is compartmentalized in the vacuole to avoid Na+ toxicity. In contrast, FL478 showed up-regulation of OsHKT1;5 and OsSOS1 in the roots, which exclude Na+ from the shoots. RNA-seq analysis showed that 4623 and 1998 differentially expressed genes (DEGs) were detected in the leaf sheaths and leaf blades of SZK, respectively. Among them, the HSP (heat shock protein) gene expression was highly up-regulated only in SZK, indicating that SZK protects against the protein damage caused by Na+ toxicity. Our findings suggest that SZK has atypical survival mechanisms under salt-stress conditions. These mechanisms offer potential traits for improving salt tolerance in rice.
Project description:Roots make the first contact with the soil environment and are the first responders of stress. These root behaviors are quantifiable and adaptive. The response of rice varieties in mechanical and salinity stress was measured in a novel experimental setup that mimics the soil environment. We analyzed the response of roots by means of SAC (Stress Adaptation Coefficient) in 28 rice varieties that include high-yield salt tolerant varieties as well as geographically isolated native rice varieties. cDNA microarray of IR64 root-tip shows about 6000 common transcripts to be differentially regulated among the two stresses and common pathways were identified. Overall, our study indicates that there is an important commonality in the molecular basis of salt and mechanical stress and presents an easy-to-perform early establishment stress screen for rice varieties.