Reproductive Development Of Rice Under Drought Stress Analysis

Rice is one of the most important crops in china and even in the world. In recent years, drought has caused severe rice yield loss, especially in those water-deficit areas.Improving rice growth and development under drought stress is important for maintaining grain yield,Previous research mainly focus on the effect of drought on root and leaf development during vegetative growth stage. However, flower, as the reproductive organ, will directly affect the grain production. It remains unclear how rice floral organs respond to water-deficit condition and therefore alter the reproductive development.Our research aims to understand the molecular mechanisms regulating this process, and finally to improve rice yield under drought stress.Responses of rice florets to drought stress at the molecular level around meiosis stage were studied in order to obtain candidate genes which can improve rice drought tolerance. We treated the rice plants at early reproductive stages with less water than normal, then hold the same SRWC (soil relative water content) for about seven days. After that, we collected the drought-treated and control rice flowers according to the the length of florets. RNA is extracted for microarray analysis. By analysis of the microarray data, we found that some genes and pathways have been induced or inhibited under drought stress, suggesting that the cell status of rice florets, such as energy metabolism, oxireduction status have been altered. The gene-chip analysis experiments were repeated in triplicate.339 genes were found to be repeatedly up-regulated and 118 genes down-regulated under drought stress.We further classify these genes according to their GO and annotations, as well as the information from published papers. The results show that some of the genes have already been reported to be involved in drought resistance, and others are new. Some genes are involved in multiple pathways such as cell metabolism and flower developement.More experiments will be necessary to further characterize their roles under drought stress.Real-Time PCR was used to confirm the microarry data,and the results are generally consistent. Based on the analysis results, several genes were chosen for further identification. Overexpression of these genes in rice flowers will allow us to understand if they can improve rice reproductive development under drought condition.