研究期間：10108~10212;Heat stress adversely affects rice production and quality and is particularly detrimental during reproductive development. The booting, flowering and grain filling are the stages of reproductive development most susceptible to high temperature (HT). HT induces sterility if pollen germination on the stigma and pollen tube elongation were inhibited. HT also enhances the rate of grain filling and consequently increases the chalky appearance of grains. Chalk predisposes the grains to break during polishing, thereby decreasing the market value of rice. Rice has evolved certain strategies, including expression of a variety of heat shock proteins, increased vesicle trafficking activity, and production of reactive oxygen species (ROS) scavenging enzymes during reproductive development to cope with such adverse effects. Nevertheless, as global warming is progressively accelerating and unanticipated extreme temperature happens more frequent than ever, the endogenous strength of aforementioned protecting function is no longer adequate, and developing technologies to effectively enhance such functions is necessary and urgent to meet the future food demand. To this end, an integrated, multidisciplinary approach is proposed in this team project with the following specific aims. They include (i) the development and screening of exogenous agrochemicals that are able to enhance expression of genes involved in pollen tube elongation and antioxidative defense system; (ii) the evaluation of the effectiveness and protecting function of the agrochemicals at different reproductive stages; (iii) the exploitation of the effective exogenous agrochemicals from laboratory to field. Results from this proposed study will also provide genetic markers for developing heat-tolerance rice cultivars in the long term perspective.
