Hu Jianan, Chang Ruokui, Yuan Yujin, Li Zhuoran, Wang Yuanhong
College of Horticulture and Landscape Architecture, Tianjin Agricultural University, Tianjin, China.
College of Engineering and Technology, Tianjin Agricultural University, Tianjin, China.
Front Microbiol. 2022 Aug 15;13:869596. doi: 10.3389/fmicb.2022.869596. eCollection 2022.
Subtilisin, a serine protease, can trigger defense responses in a wide variety of plants, both locally and systemically, to protect against pathogens. However, key residues of subtilisin to improve resistance to plant diseases remain unknown. In this study, () leaves expressing subtilisin from LJ02 were shown to improve protection against (). Furthermore, the underlying mechanism that LJ02 subtilisin improved the protective effect was explored, and the direct inhibitory effect of subtilisin on was excluded . Subsequently, reactive oxygen species (ROS) burst and upregulation of resistance-related genes in systemic leaves of further verified that subtilisin could induce systemic protection against . G307A/T308A and S213A/L214A/G215A subtilisin significantly reduced the ability to resist infection in . Furthermore, the ROS content and expression levels of resistance-related genes of both mutants were significantly decreased compared with that of wild-type subtilisin. This work identified key residues essential for the activation function of subtilisin plant immunity and was crucial in inducing plant defense responses against .
枯草杆菌蛋白酶是一种丝氨酸蛋白酶，可在多种植物中引发局部和系统的防御反应，以抵御病原体。然而，枯草杆菌蛋白酶中提高植物抗病性的关键残基仍不清楚。在本研究中，表达来自LJ02的枯草杆菌蛋白酶的（）叶片显示出对（）的防护能力增强。此外，还探究了LJ02枯草杆菌蛋白酶提高保护效果的潜在机制，并排除了枯草杆菌蛋白酶对（）的直接抑制作用。随后，（）系统叶片中的活性氧（ROS）爆发和抗性相关基因的上调进一步证实了枯草杆菌蛋白酶可诱导对（）的系统保护。G307A/T308A和S213A/L214A/G215A枯草杆菌蛋白酶显著降低了（）中抵抗（）感染的能力。此外，与野生型枯草杆菌蛋白酶相比，两种突变体的ROS含量和抗性相关基因的表达水平均显著降低。这项工作确定了枯草杆菌蛋白酶激活植物免疫功能所必需的关键残基，对诱导植物抵御（）的防御反应至关重要。
