State Key Laboratory of North China Crop Improvement and Regulation, Key Laboratory for Crop Germplasm Resources of Hebei, Hebei Agricultural University, Baoding 071001, China.
Int J Mol Sci. 2022 Mar 8;23(6):2913. doi: 10.3390/ijms23062913.
Verticillium wilt (VW), a fungal disease caused by , currently devastates cotton fiber yield and quality seriously, yet few resistance germplasm resources have been discovered in . The cotton variety Nongda601 with suitable VW resistance and high yield was developed in our lab, which supplied elite resources for discovering resistant genes. Early nodulin-like protein (ENODL) is mainly related to nodule formation, and its role in regulating defense response has been seldom studied. Here, 41 conserved ENODLs in were identified and characterized, which could divide into four subgroups. We found that was upregulated under stress and hormonal signal and displayed higher transcript levels in resistant cottons than the susceptible. The was proved to positively regulate VW resistance via overexpression and gene silencing experiments. Overexpression of significantly enhanced the expressions of salicylic acid (SA) hormone-related transcription factors and pathogenicity-related (PR) protein genes, as well as hydrogen peroxide (HO) and SA contents, resulting in improved VW resistance in transgenic . Correspondingly, in the silenced cotton, the expression levels of both phenylalanine ammonia lyase (PAL) and 4-coumarate-CoA ligase (4CL) genes significantly decreased, leading to the reduced SA content mediating by the phenylalanine ammonia lyase pathway. Taken together, played a crucial role in VW resistance by inducing SA signaling pathway and regulating the production of reactive oxygen species (ROS). These findings broaden our understanding of the biological roles of and the molecular mechanisms underlying cotton disease resistance.
黄萎病（VW）是一种由 引起的真菌病害，目前严重破坏棉花纤维的产量和质量，但 在 中发现的抗源资源很少。我们实验室培育出了适合 VW 抗性和高产的棉花品种农达 601，为发现抗性基因提供了优良资源。早期结瘤素样蛋白（ENODL）主要与根瘤形成有关，其在调节防御反应中的作用很少被研究。在这里，鉴定和表征了 中的 41 个保守的 ENODL，可以分为四个亚组。我们发现 在 胁迫和激素信号下上调，并且在抗性棉中比感病棉具有更高的转录水平。通过过表达和基因沉默实验证明 正向调控 VW 抗性。过表达 显著增强了水杨酸（SA）激素相关转录因子和致病性相关（PR）蛋白基因的表达，以及过氧化氢（HO）和 SA 含量，从而提高了转基因 对 VW 的抗性。相应地，在沉默棉花中，苯丙氨酸解氨酶（PAL）和 4-香豆酸-CoA 连接酶（4CL）基因的表达水平均显著降低，导致苯丙氨酸解氨酶途径介导的 SA 含量降低。总之， 通过诱导 SA 信号通路和调节活性氧（ROS）的产生，在 VW 抗性中发挥了关键作用。这些发现拓宽了我们对 的生物学作用以及棉花抗病性分子机制的理解。
