氧化胁迫基因3的功能分析及其在水稻上的应用

项目名称： 氧化胁迫基因3的功能分析及其在水稻上的应用

项目编号： No.31271701

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 区永祥(DavidOw)

作者单位： 中国科学院华南植物园

项目金额： 80万元

中文摘要： 氧胁迫基因3（OXS3）是新近从芥菜（B.juncea）中发现的一类胁迫耐受基因，它仅存于植物基因组中，具体功能未完全确定。该基因广谱抗重金属离子（包括镉，砷，铜和锌等）和抗氧化剂（二酰胺和四丁基过氧化氢）的胁迫。它含有一个高度保守的结构域，推测是N-乙酰转移酶或巯基转移酶的催化位点。定点突变该位点将使该基因的抗逆功能散失。OXS3成斑点样分布于核小体上，并与组蛋白H4共定位，推测OXS3可能作为一个调节因子在遭遇逆境胁迫时重构染色质来调控相关基因的表达。在水稻中OXS3基因家族有10个成员，本项目拟克隆并鉴定出水稻中主要的OXS3基因成员，研究其与镉积累的关系，及尝试通过基因工程手段培育广谱抗胁迫兼低镉积累的水稻新品系。此外，也将进一步解析该基因的功能，包括阐明互作的组蛋白组分，是否乙酰化或甲基化组蛋白，分离具有抗性的最小基因片段用于水稻育种等。

中文关键词： 镉污染；镉累积；组蛋白修饰；育种；水稻

英文摘要： OXS3 (OXIDATIVE STRESS 3) was recently discovered from Brassica juncea. Transformants expressing OXS3 or OXS3-Like cDNA exhibited enhanced tolerance to a range of metals and oxidizing chemicals, including As3+, Cu2+, Zn2+, Fe2+ , Diamide and t-BOOH. OXS3 belongs to a family of proteins that only exists in plants and shares a highly conserved domain corresponding to a putative N-acetyltransferase or thioltransferase catalytic site. Mutations within this conserved domain abolished the ability of Arabidopsis thaliana OXS3 to enhance stress tolerance in S. pombe. A subnuclear speckling pattern related to the nucleosome in discrete parts of the chromatin was found in OXS3 protein by co-localization with histone H4. It is possible that OXS3 might act as a chromatin remodeling factor for the stress response. This project aims to clone the 10 orthologs genes of OXS3 in rice. Function of individual gene will be further studied, including concrete histone species which interacts with OXS3 protein and if the histone has been modified by mean of acetylation or methylation on certain amino acid residual. The relationship between the gene function and the cadmium accumulation will be investigated. The gene fragment will be generated and minimum size of fragment still hold the stress tolerance capacity will be further used to

英文关键词： cadmium pollution；cadmium accumulation；histone modification；breeding；rice