Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile.
Wiley Interdiscip Rev Syst Biol Med. 2010 Nov-Dec;2(6):683-93. doi: 10.1002/wsbm.87.
Nitrogen (N) is an essential macronutrient for plants. In nature, N cycles between different inorganic and organic forms some of which can serve as nutrients for plants. The inorganic N forms nitrate and ammonium are the most important sources of N for plants. However, plants can also uptake and use organic N forms such as amino acids and urea. Besides their nutritional role, nitrate and other forms of N can also act as signals that regulate the expression of hundreds of genes causing modulation of plant metabolism, physiology, growth, and development. Although many genes and processes affected by changes in external or internal N have been identified, the molecular mechanisms involved in N sensing and signaling are still poorly understood. Classic reverse and forward genetics and more recently the advent of genomic and systems approaches have helped to characterize some of the components of the signaling pathways directing Arabidopsis responses to N. Here, we provide an update on recent advances to identify the components involved in N sensing and signaling in Arabidopsis and their importance for the plant response to N.
氮（N）是植物必需的大量营养素。在自然界中，N 在不同的无机和有机形式之间循环，其中一些可以作为植物的养分。无机 N 形式硝酸盐和铵是植物最重要的 N 来源。然而，植物也可以吸收和利用有机 N 形式，如氨基酸和尿素。除了它们的营养作用外，硝酸盐和其他形式的 N 还可以作为信号，调节数百个基因的表达，从而调节植物的新陈代谢、生理学、生长和发育。尽管已经确定了许多受外部或内部 N 变化影响的基因和过程，但 N 感应和信号转导所涉及的分子机制仍知之甚少。经典的反向和正向遗传学，以及最近基因组学和系统方法的出现，有助于鉴定指导拟南芥对 N 响应的信号通路中的一些成分。在这里，我们提供了最新的进展，以确定拟南芥中参与 N 感应和信号转导的成分及其对植物对 N 响应的重要性。
