水稻氮素利用效率的基因型差异与调控途径

Genotypic Differences and Regulatory Strategies of Nitrogen Use Efficiency in Rice

针对当前我国稻田土壤普遍施氮过量,水稻氮素利用效率不高的问题,综述了水稻氮素利用率与其基因型差异的生理机制和分子生理层面的研究进展。水稻氮素利用效率受多方面因素的制约,品种间的氮素利用效率差异是制约实际生产的关键因素,这种差异对水稻氮素营养特征的作用主要体现在水稻产量形成、光合特征和根系生物学特征等方面。水稻对不同形态氮素的吸收、转运和同化等过程都由相关的转运蛋白、酶类所控制,有关分子遗传方面的研究将对水稻氮素干物质生产效率和源库关系的协调提供助力。另外,氮素的同化需要能量和碳骨架,增强叶片光合碳同化的强度将驱动植株体内的氮素趋于更合理的分配,有利于氮素利用效率的提升。当前,利用水稻基因型差异的生理特性和遗传操作对调控水稻氮素利用的尝试已经有了诸多成果。未来应借助其多个遗传位点的功能特性,并通过增碳调控途径,以增强叶片作为光合同化物源强的方式更好地优化和协调源库关系,并对这些过程的生理机制开展更为深入的研究,以对改善当前的水稻氮素利用效率和促进生产提供支撑。

Under the current situation,paddy soils are generally overused with nitrogen fertilizer,and nitrogen use efficiency of rice is not high in China,so we expounded the physiological mechanisms of genotypic differences of nitrogen use efficiency and summarized the research progresses at the molecular biology perspective in rice.Nitrogen use efficiency of rice is restricted by many factors,and the difference among rice varieties is a key factor that restricts actual production,its effect on rice nitrogen nutrition characteristics is mainly reflected in rice yield formation,photosynthetic and root biological characteristics.In-depth researches for these are favorable to optimize the source-sink relationship at each stage of rice growth.The processes of absorption,transportation and assimilation for different nitrogen patterns in rice are executed by associated transporters and enzymes.Research on molecular mechanism will provide the coordination between nitrogen use efficiency for biomass production and source-sink relationship of rice.In addition,nitrogen assimilation needs to consume energy and carbon skeletons,so enhancing the intensity of leaf photosynthetic carbon assimilation can drive nitrogen allocation more rationally for the plant,which is beneficial to improve nitrogen use efficiency.Many attempts have been made to regulate rice nitrogen utilization by applying rice genotypic differences and the genetic manipulation.In the future,we should make full use of the functional characteristics of its multiple genetic locus,as well as increasing carbon provision to enhance the strength of the leaf as a source organ that provides the photosynthesis product,which is more effective to coordinate the source-sink relationship.Besides,the physiological mechanisms of these processes should be explored deeply.It is expected to provide foothold for improving the current nitrogen use efficiency and promoting production of rice.