Fungal oxysterol-binding protein-related proteins promote pathogen virulence and activate plant immunity
Fungal oxysterol-binding protein-related proteins promote pathogen virulence and activate plant immunity
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真菌氧甾醇结合蛋白相关蛋白促进病原体毒力并激活植物免疫
DOI：
10.1093/jxb/erab530
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发表时间：
2022-01-12
影响因子：
6.9
通讯作者：
Fan, Jun
中科院分区：
文献类型：
--
作者：
Chen, Meng-Meng;Yang, Si-Ru;Fan, Jun
氧甾醇结合蛋白相关蛋白（ORPs）是一类保守的脂质转移蛋白，在真核生物中密切参与多种细胞过程，但其在植物与病原体相互作用中的作用尚不清楚。研究表明，在烟草花植物中短暂表达Magnaporthe ORPs （MoORPs）可引发氧化爆发和细胞死亡；重组MoORPs处理烟草亮黄-2悬浮细胞可诱导活性氧的产生。尽管orp通常被描述为细胞内蛋白，但我们在真菌感染的大麦植物的真菌培养滤液和细胞间液中检测到moorp。更重要的是，重组拟南芥或真菌性ORPs渗入拟南芥，激活了氧化爆发、胼胝质沉积和PR1基因表达，增强了植物的抗病性，这表明ORPs可能是内源和外源的危险信号，触发了植物的先天免疫。胞外应用真菌ORPs对水杨酸和茉莉酸/乙烯信号通路产生相反的影响。油菜素内酯不敏感1-相关激酶1在orp激活的防御中是必不可少的。此外，同时敲除MoORP1和MoORP3可抑制真菌菌落径向生长和分生，而双重敲除MoORP1和MoORP2可抑制真菌对大麦和水稻的毒力。这些观察结果共同强调了MoORPs在调节植物先天免疫和促进m.o ryzae真菌发育和毒力方面的多方面作用。氧甾醇结合蛋白相关蛋白是一种新的免疫原性模式分子，是真菌病原体米瘟菌生长、发育和毒力所必需的。
Oxysterol-binding protein-related proteins (ORPs) are a conserved class of lipid transfer proteins that are closely involved in multiple cellular processes in eukaryotes, but their roles in plant-pathogen interactions are mostly unknown. We show that transient expression of ORPs of Magnaporthe oryzae (MoORPs) in Nicotiana benthamina plants triggered oxidative bursts and cell death; treatment of tobacco Bright Yellow-2 suspension cells with recombinant MoORPs elicited the production of reactive oxygen species. Despite ORPs being normally described as intracellular proteins, we detected MoORPs in fungal culture filtrates and intercellular fluids from barley plants infected with the fungus. More importantly, infiltration of Arabidopsis plants with recombinant Arabidopsis or fungal ORPs activated oxidative bursts, callose deposition, and PR1 gene expression, and enhanced plant disease resistance, implying that ORPs may function as endogenous and exogenous danger signals triggering plant innate immunity. Extracellular application of fungal ORPs exerted an opposite impact on salicylic acid and jasmonic acid/ethylene signaling pathways. Brassinosteroid Insensitive 1-associated Kinase 1 was dispensable for the ORP-activated defense. Besides, simultaneous knockout of MoORP1 and MoORP3 abolished fungal colony radial growth and conidiation, whereas double knockout of MoORP1 and MoORP2 compromised fungal virulence on barley and rice plants. These observations collectively highlight the multifaceted role of MoORPs in the modulation of plant innate immunity and promotion of fungal development and virulence in M. oryzae.Oxysterol-binding protein-related proteins are novel immunogenic pattern molecules that are required for the growth, development, and virulence of the fungal pathogen Magnaporthe oryzae.