Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
College of Grassland Science, Nanjing Agricultural University, Nanjing, 210095, China.
J Integr Plant Biol. 2022 Nov;64(11):2199-2210. doi: 10.1111/jipb.13358. Epub 2022 Oct 14.
The oomycete pathogen Phytophthora sojae is a causal agent of soybean root rot. Upon colonization of soybeans, P. sojae secretes various RXLR effectors to suppress host immune responses, supporting successful infection. Previous research has demonstrated that the RXLR effector Avh94 functions as a virulence effector, but the molecular mechanism underlying its role in virulence remains unknown. Here, we demonstrate that Avh94 overexpression in plants and pathogens promotes Phytophthora infection. Avh94 interacts with soybean JAZ1/2, which is a repressor of jasmonic acid (JA) signaling. Avh94 stabilizes JAZ1/2 to inhibit JA signaling and silencing of JAZ1/2 enhances soybean resistance against P. sojae. Moreover, P. sojae lines overexpressing Avh94 inhibit JA signaling. Furthermore, exogenous application of methyl jasmonate improves plant resistance to Phytophthora. Taken together, these findings suggest that P. sojae employs an RXLR effector to hijack JA signaling and thereby promote infection.
卵菌病原体大豆疫霉是大豆根腐病的致病因子。大豆疫霉在定殖大豆时，会分泌各种 RXLR 效应子来抑制宿主的免疫反应，从而支持成功感染。先前的研究表明，RXLR 效应子 Avh94 作为一种毒力效应子发挥作用，但它在毒力中的作用的分子机制尚不清楚。在这里，我们证明了植物和病原体中超表达 Avh94 会促进疫霉感染。Avh94 与大豆 JAZ1/2 相互作用，后者是茉莉酸（JA）信号的抑制剂。Avh94 稳定 JAZ1/2 以抑制 JA 信号，沉默 JAZ1/2 增强了大豆对 P. sojae 的抗性。此外，过表达 Avh94 的 P. sojae 株系抑制 JA 信号。此外，茉莉酸甲酯的外源应用可提高植物对疫霉的抗性。综上所述，这些发现表明，大豆疫霉利用 RXLR 效应子劫持 JA 信号，从而促进感染。
