中文摘要：

NO3^-不仅是植物从土壤中吸收的重要无机氮素形式，还是在植物体内转移的氮素形式，植物依赖硝酸盐转运体（Nitrate transporters，NRTs）参与吸收和转运NO3^-。目前，许多学者主要对NRT1．1、NRT1．2、NRT2．1进行大量研究，而对其他硝酸盐转运体的功能及调控机制研究甚少。植物体作为一个整体，吸收、转运硝酸盐是一个连续的过程，在此过程中，各硝酸盐转运体间如何相互补充、相互协调，仍有待进一步研究。文章通过对NRTs蛋白的结构、生物学功能和调控机制进行综述，旨在阐明植物吸收、转运NO3^-的生理机制，为通过基因工程手段提高作物氮素利用效率的研究提供理论依据。

英文摘要：

Nitrate （NO3^-） is not only a major inorganic form of nitrogen absorbed by plants, but also a state remobilized among different organs of plant.Higher plants use nitrate transporter （NRTs） to uptake and transport nitrate ions.Up to date, many researches focused on NRT1.1, NRT1.2, NRT2.1, while little is known about the functions and regulatory mechanisms of other forms. In the plant system as a whole, the absorption and transportation of nitrate is a continuous process. The coordination of this process with other vital processes is still need to be further investigated. In this paper, the structure, biological function and regulation of NRTs are reviewed. This paper aimed at expounding the molecular and physiological mechanisms of absorption and transportation of nitrate in plants, and provides guidance for improvement of crops＇ nitrogen efficiency.