油菜高效碳同化的生理代谢特征及调控机理研究

Yield increases have ceased over the past decade, indicating the existence of a yield barrier. Improvement of the photosynthetic performance represents a promising strategy to overcome this yield barrier, especially converting the photosynthetic pathway of C3 plants into C4. However there might be a big and long workload if using genetic engineering technique. Fortunately it has confirmed that C4 pathway also exists in C3 plants. Therefore, from the aspect of cultivation and physiological regulation, this project is going to illustrate the cellular physiological and metabolic characteristics of high-efficiency pathway plants through evaluating the Biochemical, Structural, and molecular properties of different efficiency-pathway plants. Furthermore, the responses of different efficiency-pathway plants to exogenous growth regulators and environmental stress are also going to investigated to explore the regulation mechanism of high-efficiency pathway combined with the RNA-Seq analysis. This is the first time to study the physiological and metabolic characteristics and regulation mechanism using hybridization between C3 crop and C3-C4 plants. It is expected to create a crucial model for improving the photosynthetic efficiency of C3 crops, and also providing theoretical support for technology innovation to break through the bottleneck of crop yield.

依靠传统的育种栽培措施促进油菜产量的提升已经发展到一个瓶颈阶段。寻找新的途径来打破当前产量瓶颈至关重要。将C4途径导入C3作物是目前最为理想的途径之一。基因工程方法工程量大且耗时长。因此本项目拟从栽培生理角度着手，通过比较芸薹属C3-C4中间型植物B.gravinae与C3作物油菜杂交种后代中不同碳同化效率植株生理代谢的差异，研究碳同化途径转移后的生理变化规律，明确油菜高效碳同化途径运行的内部生理代谢特征。并结合RNA-seq技术获得与碳同化途径相关的差异表达基因，通过基因比对和相应功能分析，初步明确高效碳同化的调控机理。然后根据不同碳同化效率的株系对外源激素和环境调控的生理响应特征，探讨高效碳同化油菜的调控模式。本项目首次在农作物上利用不同碳同化途径植物杂交的方法开展C3作物的高效碳同化生理特征及调控机理研究，为今后高光效栽培调控开辟新的途径，为C3作物的C4化研究提供新的思路和方法。

提高作物的碳同化效率是作物增产的有效手段之一。主要研究内容与结果如下：（1）通过属间杂交工作，开展不同碳同化材料的创制，获得了遗传背景基本一致的不同光效碳同化油菜材料；（2）对不同种质资源材料的油菜碳同化效率进行了正常和干旱逆境两种不同处理条件下的光合特征筛选研究，初步筛选出了不同条件下的碳同化效率差异材料；（3）开展了不同油菜种质材料的氮素光效评价，根据油菜碳同化与氮同化效率的高度相关性，建立氮高效种质评价体系为碳高效种质筛选提供重要参考；（4）通过外源物质诱导油菜碳同化相关生理特征变化与分子表达差异研究，初步明确油菜高效碳同化响应机理，并筛选出褪黑素、AM1和富勒醇3种促进油菜实现高效碳同化的外源调节物质；（5）根据油菜光合特点建立了密植高光效栽培技术，提出适当增密增氮是油菜实现高效碳同化提升产量品质的关键栽培措施。本项目首次在农作物上开展C3作物的高效碳同化生理特征及调控机理研究，为今后高光效栽培调控开辟新的途径，为C3作物的C4化研究提供新的思路和方法。