State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China.
Int J Mol Sci. 2022 Jan 3;23(1):508. doi: 10.3390/ijms23010508.
Kiwifruit canker, caused by pv. (), is a destructive pathogen that globally threatens the kiwifruit industry. Understanding the molecular mechanism of plant-pathogen interaction can accelerate applying resistance breeding and controlling plant diseases. All known effectors secreted by pathogens play an important role in plant-pathogen interaction. However, the effectors in and their function mechanism remain largely unclear. Here, we successfully identified a T3SS effector HopAU1 which had no virulence contribution to , but could, however, induce cell death and activate a series of immune responses by agroinfiltration in , including elevated transcripts of immune-related genes, accumulation of reactive oxygen species (ROS), and callose deposition. We found that HopAU1 interacted with a calcium sensing receptor in (NbCaS) as well as its close homologue in kiwifruit (AcCaS). More importantly, silencing by RNAi in greatly attenuated HopAU1-triggered cell death, suggesting CaS is a crucial component for HopAU1 detection. Further researches showed that overexpression of in significantly enhanced plant resistance against and , indicating that serves as a promising resistance-related gene for disease resistance breeding. We concluded that HopAU1 is an immune elicitor that targets CaS to trigger plant immunity.
猕猴桃溃疡病由 pv. 引起（），是一种具有破坏性的病原体，它对全球猕猴桃产业构成威胁。了解植物-病原体相互作用的分子机制可以加速应用抗性育种和控制植物病害。所有已知的病原体分泌的效应子在植物-病原体相互作用中都起着重要的作用。然而， 和它们的作用机制在很大程度上仍然不清楚。在这里，我们成功地鉴定了一个 T3SS 效应子 HopAU1，它对 没有毒力贡献，但可以通过农杆菌浸润在 中诱导细胞死亡和激活一系列免疫反应，包括免疫相关基因的转录物升高、活性氧（ROS）的积累和胼胝质的沉积。我们发现 HopAU1 与 在 （NbCaS）中的钙感应受体及其在猕猴桃中的近同源物（AcCaS）相互作用。更重要的是，在 中通过 RNAi 沉默 大大减弱了 HopAU1 触发的细胞死亡，表明 CaS 是 HopAU1 检测的关键组成部分。进一步的研究表明，在 中过表达 显著增强了植物对 和 的抗性，表明 是一种有前途的抗病相关基因，可用于抗病育种。我们得出结论，HopAU1 是一种免疫激发子，它以 CaS 为靶标触发植物免疫。
