植物氮素吸收、运转和分配调控机制研究

Absorption, transportation and regulation of nitrogen element in plants

氮是影响植物生长发育的必需大量营养元素之一,是叶绿素、氨基酸、核酸、次生代谢产物的重要组分。目前在农业生产中氮肥施用过量、效率低下、对环境造成不利影响的问题非常严重。NH_4^+-N和NO_3^--N是植物吸收利用的主要无机氮素形态,植物在演替过程中逐渐形成高效吸收和利用氮素的生理和分子机制。本文重点综述了植物根系从土壤中吸收NH_4^+-N和NO_3^--N,再通过木质部和韧皮部转运至地上部并在各器官进行分配、利用的生理过程和分子调控机制研究进展,并对今后的氮素吸收、运转和分配的研究重点提出展望,这为生产上促进植物氮素吸收和利用,提高氮效率和增强农业生产力提供了理论基础。

Nitrogen is one of the essential nutrient elements that affect plant growth and development, and also an important component of chlorophyll, amino acid, nucleic acid and secondary metabolites. At present, the problems of excessive application, low efficiency and adverse impact of nitrogen fertilizer on the environment in agricultural production are very serious. NH4+-N and NO3--N are the main forms of inorganic nitrogen absorbed and utilized by plants. A set of physiological and molecular regulation mechanisms for efficient absorption and utilization of nitrogen have been gradually formed. In this paper, we reviewed the advances about uptakes of NH4+-N and NO3--N by plant roots from soil,the physiological processes and molecular regulation mechanisms of nitrogen transport to the above-ground part through xylem and phloem for distribution and utilization in different organs in plants. The future research emphasis on nitrogen uptake,operation and distribution was also prospected. These provide a theoretical basis for promoting plant nitrogen uptake and utilization, improving nitrogen efficiency and enhancing agricultural productivity in production.