Expression-Regulation Of Related Genes Involving In Early Indica Rice Endosperm Filling To High Temperature Stress

A comparative analysis on expression profiles of early indica rice endosperm related gene was maked in this experiment,with early indica rice plant being exposed to two temperature treatments(the mean dairy air temperature,22℃and 32℃for optimum temperature treatment and high temperature treatment, respectively)in chambers.Samples were taken at different filling stages.The differential expression responses of key-enzyme with regard to starch synthesis metabolism(GBSS,SSS,SEB,DBE)as well as their distinct isoforms genes,which have something with early indica rice starch quality were detected by Real-time Fluorescence Quantitative PCR(FQ-PCR).The experiment was indicated as follow:1.There were significant differences on expression response of gene related to endosperm development that exposed to high temperature stress,in which a large number of genes relating carbohydrate metabolism,the protein and amino-acid metabolism,as well as the transportation exhibited up-regulated expression,while the expression of genes involving in nutrition storage were down-regulated.The expression response of genes involving in cell nuclear and starch synthesis family to high-temperature stress varied with different filling stage,in which some genes were up-reglaluted while others were down- reglaluted.2.The diffferntial expression was also found for the response of starch synthesis genes early indica rice endosperm to high temperature stress.SSSI and SSSⅢa were the main isoforms of SSS which are expressed,their expression were up-regulated gradually in low temperature,down-regulated expression was found in early indica rice endosperm when it was exposed to high temperature stress;The relative expression of GBSSⅠin early indica rice endosperm at filling stage was far higher than that of GBSSⅡ.It was up-regulated expression when involved in low temperature,whereas it was down-regulated expression to high temperature stress. The expression response,to which in different temperature treatment of SBEⅠ,was similar with that of SBEⅢ.It was significant that expressions of SBEⅠand SBEⅢtreated with low temperature were much higher than that to high temperature stress.The different expression response of SBEⅣin early indica rice endosperm was not found in 12th day after anthesis,but it rised sharply in 16th day after anthesis when early indica rice grains was treated with high temperature stress.The expression response of IDBE 1 and the IDBE2 was up-regulated gradually along with filling stages,the range and velocity of up-regulated in low temperature were much moer larger and higher than those exposed to temperature stress.The expression response of IDBE3 was similar with that of RBE in early indica rice endosperm. Their expression responses were up-regulated along with filling gradually,while to some extent,they were down-regulated involving in high temperature stress.