水稻為我國最重要的農作物之一，但高溫易造成水稻不稔與米粒充實減少等現象，導致稻米產量降低。為瞭解水稻耐熱機制與降低高溫對水稻造成的傷害，由T–DNA 插入基因活化水稻突變株種原庫篩選具耐熱性突變株和建立水稻第一族小分子量熱休克蛋白質基因的轉錄股與反轉錄股轉殖株。本計劃即針對上述 T–DNA 插入基因活化水稻突變株與第一族小分子量熱休克蛋白質基因轉殖株進行深入分析， 藉此建立水稻耐熱性分子標記、改善水稻栽培條件和培育具熱耐性的新品種水稻。計畫分三年進行， 主要工作項目包括：（ 一）測定T–DNA 插入基因活化水稻突變株與第一族小分子量熱休克蛋白質基因過量表現及抑制表現之水稻轉殖株在常溫及溫度逆境下生長、結穗、稔實率與稻米品質等情形；篩選T–DNA 插入基因活化水稻突變株中溫度調控相關基因。（ 二） 探討T–DNA 插入基因活化水稻突變株中溫度調控相關基因生理功能； 研究水稻第一族小分子量熱休克蛋白質對水稻耐熱性的影響。（三）建立溫度調控基因轉殖株，確認篩得之溫度調控基因可調控水稻生長過程中的生理反應與耐熱性。（四）溫度調控基因誘導條件分析，建構水稻耐熱環境， 改善水稻栽培條件， 同時培育對高溫逆境具高耐性的新品種水稻。 Rice is one of the most important crops in Taiwan. However, the grain yield was reduced by sterility and decreased rice grain filling under heat stress. To understand the mechanism of thermoresistance and reduce the harmful effects caused by heat stress in rice, we have screened putative thermo-tolerant lines from rice T-DNA tagging mutants and constructed transgenic rice plant using the sense strand and antisnese fragment of rice class I small heat shock protein genes. In this three-year project, our goals are to characterize and further study the thermoresistance of the thermo-tolerant T-DNA tagging mutants and class I small heat shock protein gene transgenic rice plants, understand the mechanism for conferring thermo-tolerance of rice, improve rice grain yield and quality under heat stress, and try to breed new thermo-tolenant rice line based on our results . Our works include: (1) to assay the growth, development, fertility, and grain quality of thermo-tolerant T-DNA tagging mutants and transgenic rice plants with expression of sHSP-CIs constitutively and reduction in the transcription of one or all sHSPs under normal temperature or high temperature conditions. (2) to study the physiological functions of rice class I small heat shock proteins and the effects of the class I small heat shock proteins for rice thermo-tolerance. (3) to screen the mutated genes of thermo-tolenant T-DNA tagging mutants and construct their transgenic rice plants to identify the roles on thermotolerance, fertility, and grain quality of rice. (4) to improve growth conditions and breed new rice line with higher thermo-tolerant ability. 研究期間：9908 ~ 10007
