Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada.
Carleton University, Department of Biology, 1125 Colonel By Dr., Ottawa, ON K1S 5B6, Canada.
J Exp Bot. 2021 Sep 30;72(18):6628-6639. doi: 10.1093/jxb/erab285.
Plants perceive externally produced microbe-associated molecular patterns (MAMPs) and endogenously produced danger-associated molecular patterns (DAMPs) to activate inducible immunity. While several inducible immune responses have been observed during Fusarium graminearum infection, the identity of the signaling pathways involved is only partly known. We screened 227 receptor kinase and innate immune response genes in Arabidopsis to identify nine genes with a role in F. graminearum resistance. Resistance-promoting genes included the chitin receptors LYK5 and CERK1, and the reactive oxygen species (ROS)-producing NADPH oxidase RbohF, which were required for full inducible immune responses during infection. Two of the genes identified in our screen, APEX and the PAMP-induced peptide 1 (PIP1) DAMP receptor RLK7, repressed F. graminearum resistance. Both RbohF and RLK7 were required for full chitin-induced immune responses and PIP1 precursor expression was induced by chitin and F. graminearum infection. Together, this indicates that F. graminearum resistance is mediated by MAMP and DAMP signaling pathways and that chitin-induced signaling is enhanced by PIP1 perception and ROS production.
植物感知外部产生的微生物相关分子模式（MAMPs）和内源性产生的危险相关分子模式（DAMPs），以激活诱导免疫。虽然在禾谷镰刀菌感染过程中观察到了几种诱导免疫反应，但参与的信号通路的身份仅部分已知。我们筛选了拟南芥中的 227 个受体激酶和先天免疫反应基因，以鉴定出在禾谷镰刀菌抗性中起作用的 9 个基因。促进抗性的基因包括几丁质受体 LYK5 和 CERK1，以及产生活性氧（ROS）的 NADPH 氧化酶 RbohF，它们是感染过程中完全诱导免疫反应所必需的。我们在筛选中鉴定出的两个基因，APEX 和 PAMP 诱导肽 1（PIP1）DAMP 受体 RLK7，抑制了禾谷镰刀菌的抗性。RbohF 和 RLK7 都需要完全的几丁质诱导免疫反应，并且 PIP1 前体的表达受到几丁质和禾谷镰刀菌感染的诱导。综上所述，这表明禾谷镰刀菌的抗性是由 MAMP 和 DAMP 信号通路介导的，并且 PIP1 感知和 ROS 产生增强了几丁质诱导的信号。
