超表达嘌呤合成途径基因VAL1调控水稻光适应的生理机制研究

Photosynthetic acclimation research aimed at increasing rice yield has become a frontier science issues for rice breeding and cultivation. The weak photosynthetic acclimatization is the main factor affecting the photosynthate accumulation during the early growth stage of rice. It is of great significance to carry out photosynthetic acclimation research to achieve high rice yield, ensure food security and increase farmers' income. In this project, we aim to increase the rice yield in the oligo-sunshine region, especially in the southwestern cultivated areas of China. Start by determining the limiting factor for increasing photosynthetic acclimatization, the rice plants (VAL1-OE), overexpressing a gene involved in the de novo purine biosynthesis pathway and obtained in the previous study, are used as materials for this project. In particular, these plants have advantages of adapting to low light and high light at the same time. Through transcriptomics, metabolomics, proteomics and photosynthetic pathway analysis, the differential regulation factors in photosynthetic pigment synthesis, light energy absorption and distribution, photosynthetic electron flow distribution, photorespiration and photosynthetic carbon assimilation between VAL1-OE and Wild-type will be studied to (A) clarify the physiological basis of light absorption and distribution in the photosynthesis system of VAL1-OE rice, (B) definitude the physiological regulatory pathways for optimizing photosynthetic electron flow distribution, and (C) reveal the physiological regulatory mechanism of adapting to low light and high light at the same time in VAL1-OE rice. Research results of this project will provide reference for mining rice yield potential in the oligo-sunshine area and screening rice resources for high photosynthetic acclimatization.

以提高水稻产量为目的的光合适应性研究已成为水稻育种学和栽培学共同关注的热点问题。低光光合适应性弱是影响水稻生育前期物质累积的主要因素，开展光合适应性研究对实现水稻高产、保障粮食安全和农民增收具有重要意义。本项目针对寡日照限制我国西南栽培区水稻产量提升这一问题，从确定光合适应性提升的限制因子入手，以前期研究获得的超表达嘌呤合成途径基因水稻株系（VAL1-OE）为材料，利用其同时适应低光和高光环境这一优势，通过转录组学、代谢组学、蛋白组学和光合途径分析等手段，研究其与野生型材料在不同光照下光合色素合成、光能吸收与分配、光合电子传递、光呼吸以及光合碳同化效率等生理途径的差异调控因子，阐明VAL1-OE提高光能吸收、平衡光能分配的生理基础，明确其优化光合电子流分配的调控途径，揭示VAL1-OE实现同时适应低光和高光环境的调控作用机制，为挖掘寡日照地区水稻增产潜力，筛选光照广适稻种资源提供参考。

开展以提高水稻产量为目的的光合适应性研究对实现水稻高产、保障粮食安全和农民增收具有重要意义。本项目针对寡日照限制我国西南栽培区水稻产量提升这一问题，从确定光合适应性提升的限制因子入手，以前期研究获得的超表达嘌呤合成途径基因水稻株系（VAL1-OE）为材料，利用其同时适应低光和高光环境这一优势，研究了其与野生型材料在不同光照下光合色素合成、光能吸收与分配、光合电子传递、光呼吸以及光合碳同化效率等生理途径的差异调控因子，阐明了VAL1-OE提高光能吸收、平衡光能分配的生理基础，明确了其优化光合电子流分配的调控途径，揭示了VAL1-OE实现同时适应低光和高光环境的调控作用机制，提出了以VAL1超表达水稻为亲本，在实现高光合能力的同时，培育高叶面积表型材料，提高光合作用面积是进一步提高该水稻材料干物质累积量和产量的突破口。研究成果可为挖掘寡日照地区水稻增产潜力，筛选光照广适稻种资源提供参考。