小麦是世界范围内最重要的粮食作物之一。近几十年来,肥料,特别是氮(N),越来越多地用于最大限度地提高小麦生产力。然而,很大比例的N没有被植物利用,实际上流失到环境中,造成严重的环境污染。因此,在低氮条件下生长的小麦中,通过有效的生理和生化过程实现低氮的最佳状态对于农业可持续性非常重要。尽管小麦中与氮胁迫相关的氮捕获已成为一个重要的研究课题,这种植物如何适应和应对氮饥饿尚未完全阐明。这篇综述总结了有关小麦植物响应氮饥饿而激活的信号机制的最新知识。此外,我们用在其他植物中获得的发现填补了这个主题的假定空白,主要是大米,玉米,和拟南芥。已确定植物激素在感知环境N饥饿并将该信号转化为N转运蛋白的调节和表型适应中起着至关重要的作用。蛋白激酶和关键激酶和磷酸酶所起的关键作用,如MAPK和PP2C,以及转录因子的多方面功能,如NF-Y,MYB,DOF,和WRKY,还讨论了调节其靶基因(蛋白质)的表达水平以实现低N耐受性。通过根分支和稀疏优化根系结构(RSA),N习得和同化的改进,和微调自噬是植物对N饥饿做出反应的关键策略。根据这些发现,我们试图构建RSA修饰和N摄取的调控网络,运输,同化,和重新动员。
Wheat is one of the most important food crops worldwide. In recent decades, fertilizers, especially nitrogen (N), have been increasingly utilized to maximize wheat productivity. However, a large proportion of N is not used by plants and is in fact lost into the environment and causes serious environmental pollution. Therefore, achieving a low N optimum via efficient physiological and biochemical processes in wheat grown under low-N conditions is highly important for agricultural sustainability. Although N stress-related N capture in wheat has become a heavily researched subject, how this plant adapts and responds to N starvation has not been fully elucidated. This
review summarizes the current knowledge on the signaling mechanisms activated in wheat plants in response to N starvation. Furthermore, we filled the putative gaps on this subject with findings obtained in other plants, primarily rice, maize, and Arabidopsis. Phytohormones have been determined to play essential roles in sensing environmental N starvation and transducing this signal into an adjustment of N transporters and phenotypic adaptation. The critical roles played by protein kinases and critical kinases and phosphatases, such as MAPK and PP2C, as well as the multifaceted functions of transcription factors, such as NF-Y, MYB, DOF, and WRKY, in regulating the expression levels of their target genes (proteins) for low-N tolerance are also discussed. Optimization of root system architecture (RSA) via root branching and thinning, improvement of N acquisition and assimilation, and fine-tuned autophagy are pivotal strategies by which plants respond to N starvation. In light of these findings, we attempted to construct regulatory networks for RSA modification and N uptake, transport, assimilation, and remobilization.