Project description:Intensive application of inorganic nitrogen underlies marked increase in crop production yet imposes detrimental impact on ecosystems, hence it is crucial for future sustainable agriculture to improve nitrogen-use efficiency (NUE). Here we report the genetic basis of NUE associated with the local soil adaptation in rice. With a diverse rice germplasm panel collected from different ecogeographic regions, we performed genome-wide association study on tillering response to nitrogen (TRN), the most correlated trait with NUE of rice, and identified OsTCP19 as a modulator of TRN via transcriptionally responding to nitrogen and targeting to Dwarf and Low-Tillering (DLT), a tiller-promoting gene. A 29-bp InDel in OsTCP19 promoter confers differential transcription response to nitrogen and TRN variation among rice varieties. The high-TRN allele of OsTCP19 (OsTCP19-H) is prevalent in wild rice population, but largely lost in modern cultivars correlating with increased local soil nitrogen content, suggesting that it might have contributed to geographic adaptation in rice. Introgression of OsTCP19-H into modern rice cultivars boosts grain yield and NUE under low or moderate nitrogen levels, demonstrating its enormous potential for rice breeding and environment amelioration through reducing nitrogen application.
Project description:Iron (Fe) is an essential element to plants, but can be harmful if accumulated to toxic concentrations. Fe toxicity can be a major nutritional disorder in rice (Oryza sativa) when cultivated under waterlogged conditions, as a result of excessive Fe solubilization of in the soil. However, little is known about the basis of Fe toxicity and tolerance at both physiological and molecular level. Here we aim at understand the genotypic differences in two rice cultivars with contrasting phenotypes under Fe toxicity.
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:In this study, we aim to generate genome-scale DNA methylation profiles at single-base resolution in different rice cultivars (IR64, Nagina 22 and Pokkali) under control and stress conditions. Using high-throughput whole genome bisulfite Sequencing, we generated DNA methylation maps covering the vast majority of cytosines in the rice genome. More than 152 million high quality reads were obtained for each tissue sample using Illumina platform. We discovered extensive DNA methylation in rice cultivars, identified the context and level of methylation at each site.Numerous differentially methylated regions (DMRs) among different cultivars under control and stress conditions were identified and many of them were associated with differential gene expression. The high resolution methylome maps of different rice genotypes and differentially methylated regions will serve as reference for understanding the epigenetic regulation of stress responses in plants.
Project description:We used RNA-Seq to query the Chlamydomonas reinhardtii transcriptome for regulation by CO2 concentration and by the transcription regulator CIA5(CCM1). Both CO2 concentration and CIA5 are known to play roles in induction of an essential CO2-concentrating mechanism (CCM), but the degree of interaction and the extent of global regulation beyond the CCM were not previously understood. We compared the transcriptome of a wild type strain vs. a cia5 strain under 3 CO2 supply conditions: high CO2 (H-CO2; 5%); low CO2 (L-CO2; 0.03 to 0.05%); and very-low CO2 (VL-CO2; <0.02%). Our goals were to: 1) reveal candidate genes that, through changes in their expression, distinguish multiple acclimation states induced by H-CO2, L-CO2, and VL-CO2; 2) reveal genes regulated directly or indirectly by CIA5; and 3) reveal genes responding to the interaction between CIA5 and changes in CO2 concentration. Our results revealed a small group of genes as encoding putative Ci transporters based on their expression patterns. The results also showed a massive and much broader impact on global gene regulation by CIA5/CCM1, which directly or indirectly affected 15% of the Chlamydomonas genome. The transcriptomes under L-CO2 and VL-CO2 conditions were not significantly different, suggesting that these two acclimation states must be controlled by mechanisms operating beyond transcript abundance.
Project description:In this study, we aim to generate genome-scale DNA methylation profiles at single-base resolution in different rice cultivars (IR64, Nagina 22 and Pokkali) under control and stress conditions. Using high-throughput whole genome bisulfite Sequencing, we generated DNA methylation maps covering the vast majority of cytosines in the rice genome. More than 152 million high quality reads were obtained for each tissue sample using Illumina platform. We discovered extensive DNA methylation in rice cultivars, identified the context and level of methylation at each site.Numerous differentially methylated regions (DMRs) among different cultivars under control and stress conditions were identified and many of them were associated with differential gene expression. The high resolution methylome maps of different rice genotypes and differentially methylated regions will serve as reference for understanding the epigenetic regulation of stress responses in plants. Whole genome bisulfite sequencing of seven control/stressed samples from three rice cultivars (IR64, N22 and Pokkali)
Project description:When plants are continuously treated with high concentration of CO2, they will show different physiological and biochemical characteristics due to the different conditions of the plants themselves and the environment, and the leaves, as the main organ of gas exchange between plants and the outside world, will first respond to CO2 stress through photosynthesis and respiration when the atmospheric concentration of CO2 rises. In this study, tetraploid Sophora japonica was selected as the research object to analyze the stomatal movement pattern and the changes of photosynthesis and respiration under high CO2 culture conditions, and we found that ROS and NO were synthesized and participated in the regulation of CO2-mediated stomatal closure, and we also proved that the alternate respiration pathway could alleviate the oxidative damage caused by high CO2 concentration. Combined with the proteomics approach, the key proteins responsive to high concentration of CO2 were mined according to the changes of differential proteins under different treatment conditions, with the aim of laying a theoretical foundation for the study of elucidating the response mechanism of tetraploid Sophora japonica under high concentration of CO2 treatment.
Project description:Analysis of rice leaves (V2 stage) in response to a short treatment with very high CO2 concentration in the dark, using standard atmosphere as control. Results provide insight into molecular mechanisms occurring in response to these extreme conditions, which are often used in the food industry. V2 rice plants were either treated with 30% [CO2] or kept under normal atmosphere (control) for 6 h at 27ºC in the dark. Two biological replicates per treatment (30% [CO2] and control), each encompassing the leaves of ten plants, were analyzed.