Yadav Vivek, Wang Zhongyuan, Wei Chunhua, Amo Aduragbemi, Ahmed Bilal, Yang Xiaozhen, Zhang Xian
State Key Laboratory of Crop Stress Biology in Arid Areas, College of horticulture, Northwest A&F University, Xianyang 712100, China.
College of Agronomy, Northwest A&F University, Xianyang 712100, China.
Pathogens. 2020 Apr 23;9(4):312. doi: 10.3390/pathogens9040312.
Pathogens hitting the plant cell wall is the first impetus that triggers the phenylpropanoid pathway for plant defense. The phenylpropanoid pathway bifurcates into the production of an enormous array of compounds based on the few intermediates of the shikimate pathway in response to cell wall breaches by pathogens. The whole metabolomic pathway is a complex network regulated by multiple gene families and it exhibits refined regulatory mechanisms at the transcriptional, post-transcriptional, and post-translational levels. The pathway genes are involved in the production of anti-microbial compounds as well as signaling molecules. The engineering in the metabolic pathway has led to a new plant defense system of which various mechanisms have been proposed including salicylic acid and antimicrobial mediated compounds. In recent years, some key players like phenylalanine ammonia lyases (PALs) from the phenylpropanoid pathway are proposed to have broad spectrum disease resistance (BSR) without yield penalties. Now we have more evidence than ever, yet little understanding about the pathway-based genes that orchestrate rapid, coordinated induction of phenylpropanoid defenses in response to microbial attack. It is not astonishing that mutants of pathway regulator genes can show conflicting results. Therefore, precise engineering of the pathway is an interesting strategy to aim at profitably tailored plants. Here, this review portrays the current progress and challenges for phenylpropanoid pathway-based resistance from the current prospective to provide a deeper understanding.
病原体侵袭植物细胞壁是触发植物防御苯丙烷类途径的首要推动力。苯丙烷类途径基于莽草酸途径的少数中间体，因病原体导致的细胞壁破损而分支产生大量化合物。整个代谢途径是一个由多个基因家族调控的复杂网络，在转录、转录后和翻译后水平上展现出精细的调控机制。该途径的基因参与抗菌化合物以及信号分子的产生。代谢途径的工程改造已形成一种新的植物防御系统，针对该系统已提出了包括水杨酸和抗菌介导化合物在内的多种机制。近年来，有人提出苯丙烷类途径中的一些关键参与者，如苯丙氨酸解氨酶（PALs），具有广谱抗病性（BSR）且不会造成产量损失。如今我们掌握了比以往更多的证据，但对于那些在微生物攻击时协调苯丙烷类防御快速、协同诱导的基于该途径的基因却了解甚少。途径调节基因的突变体出现相互矛盾的结果也就不足为奇了。因此，对该途径进行精确工程改造是培育具有理想特性植物的一个有趣策略。在此，本综述从当前视角阐述了基于苯丙烷类途径的抗性研究的现状与挑战，以期提供更深入的理解。
