Project description:Rice (Oryza sativa), the major staple food crop is being cultivated under varying ecosystems ranging from irrigated lowland to rainfed upland environments. Improvement in the rice production under drought prone unfavourable environment depends on the development of drought tolerant genotypes which needs thorough understanding of physiological and molecular events behind the tolerance mechanism. There is considerable genetic variation for drought tolerance mechanism within the cultivated gene pool. To understand the diversity of drought response, two indica rice genotypes namely, i) Apo, an up-land drought tolerant indica veriety from Philippines and ii) IR64, a popular high yielding drought susceptible genotype were selected 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 control and drought stressed conditions during vegetative phase. Keywords: Drought response
Project description:One of the serious constraints to realize high level of rice crop productivity in agriculture has been due to Soil Water Stress (SWS) situation that growing plants often face. In order to increase or maintain the crop productivity in SWS situation, our initial aim is to understand the drought response mechanism in different genotypes of rice. For thorough analysis of SWS situation in rice we have taken here two wild genotypes of rice namely Oryza nivara, Oryza rufipogon and three Oryza sativa indica cultivars namely Nagina-22, IR20 and Vandana, where IR20 is known to be susceptible and Vandana is known to be tolerant under SWS condition [GSE49364 and the current study]. Global analysis of transcript profiling under SWS condition reveal the actual picture of genes responsive to stress situation in different genetic background of rice. Furthermore it would help us in the selection of most desirable resource for crop breeding without compromising the yield of crop. We used the 44k rice Oligoarray from Agilent technologies to study the expression profiles from five rice genotypes during vegetative (Veg) and grain-filling (GF) stages under varying water conditions, viz. Before Stress (BS), After Stress (AS) and After Recovery (AR).
Project description:Crown roots differentiate from stem base in rice. In this study, we followed gene expression in stem base of two Vietnamese indica rice varieties that belong to two haplotypes defining a QTL associated with crown root number. We used microarrays to look for the gene differentially expressed in stem base of two varieties.
Project description:Rice (Oryza sativa, spp. Indica, cv. 93-11) plants were grown in a Conviron PGR 15 growth chamber using precise control of temperature, light, and humidity.<br>Diurnal (driven) conditions included 12L:12D light cycles and 31C/20C thermocycles in three different combinations. These were: photocycles (LDHH), 12 hrs. light (L)/12 hrs. dark (D) at a constant temperature (31C; HH); photo/thermocycles (LDHC): 12 hrs. light (L) /12 hrs. dark (D) with a high day temperature (31C) and a low night temperature (20C); and thermocycles (LLHC): continuous light (LL) with 12 hrs. high/12 hrs. low temperature (31C, day; 20C, night). Light intensity and relative humidity were 1000 micromol m-2s-2 and 60%, respectively.<br>Three-month-old rice plants were entrained for at least one week under the respective condition prior to initiation of each experiment. Leaves and stems from individual rice plants were collected every four hours for 48 hrs in driven (diurnal) conditions followed by a two day freerun spacer under continuous light/temperature followed by two additional days of sampling under the same continuous free run condition.
Project description:An indica rice cultivar FR13A, is widely grown as submergence tolerant variety and can withstand submergence up to two weeks. The tolerance is governed by a major QTL on chromosome 9 and represented as sub1. Recently the gene for sub1 has been mapped and cloned. However, the trait is governed by several QTLs and not by a single gene. To understand the mechanism of submergence 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 submerged conditions at seedling stage. Keywords: Mechanism of submergence 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. Keywords: Mechanism of salt tolerance
Project description:<p>Pigmented rice (<em>Oryza sativa L.</em>) is a rich source of nutrients, but pigmented lines typically have long life cycles and limited productivity. Here we generated genome assemblies of 5 pigmented rice varieties and evaluated the genetic variation among 51 pigmented rice varieties by resequencing an additional 46 varieties. Phylogenetic analyses divided the pigmented varieties into four varietal groups: Geng-japonica, Xian-indica, circum-Aus and circum-Basmati. Metabolomics and ionomics profiling revealed that black rice varieties are rich in aromatic secondary metabolites. We established a regeneration and transformation system and used CRISPR-Cas9 to knock out three flowering time repressors (Hd2, Hd4 and Hd5) in the black Indonesian rice Cempo Ireng, resulting in an early maturing variety with shorter stature. Our study thus provides a multi-omics resource for understanding and improving Asian pigmented rice.</p>
Project description:Rice (Oryza sativa), the major staple food crop is being cultivated under varying ecosystems ranging from irrigated lowland to rainfed upland environments. Improvement in the rice production under drought prone unfavourable environment depends on the development of drought tolerant genotypes which needs thorough understanding of physiological and molecular events behind the tolerance mechanism. There is considerable genetic variation for drought tolerance mechanism within the cultivated gene pool. To understand the diversity of drought response, two indica rice genotypes namely, i) Apo, an up-land drought tolerant indica veriety from Philippines and ii) IR64, a popular high yielding drought susceptible genotype were selected 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 control and drought stressed conditions during vegetative phase. Keywords: Drought response We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice leaf tissues during drought stress. We used two contrasting rice genotypes (IR64 drought susceptible and Apo drought tolerant) differing in their degree of drought tolerance. Plants were grown under green house conditions and drought stress was imposed on 33rd DAS. Leaf sampling was done in both control and drought stressed plants after 6 days of drought stress. Three replications of microarray experiments were carried out by hybridizing the control samples against the drought stressed samples.