Sclerotinia disease is one of the most devastating fungal diseases worldwide, as it reduces the yields of many economically important crops. Pathogen-secreted effectors play crucial roles in infection processes. However, key effectors of Ciboria shiraiana, the pathogen primarily responsible for sclerotinia disease in mulberry (Morus spp.), remain poorly understood. In this study, we identified and functionally characterized the effector Cs02526 in C. shiraiana and found that Cs02526 could induce cell deathin a variety of plants. Moreover, Cs02526-induced cell death was mediated by the central immune regulator BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1 (BAK1), dependent on a 67-amino acid fragment. Notably, Cs02526 homologues were widely distributed in hemibiotrophic and necrotrophic phytopathogenic fungi, but the homologues failed to induce cell death in plants. Pre-treatment of plants with recombinant Cs02526 protein enhanced resistance against both C. shiraiana and Sclerotinia sclerotiorum. Furthermore, the pathogenicity of C. shiraiana was diminished upon spraying plants with synthetic dsRNA-Cs02526. In conclusion, our findings highlight the cell death-inducing effector Cs02526 as a potential target for future biological control strategies against plant diseases.

中文翻译：

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来自 Ciboria shiraiana 的效应子 Cs02526 诱导细胞死亡并调节植物免疫力


核盘菌病是全世界最具破坏性的真菌病害之一，因为它降低了许多重要经济作物的产量。病原体分泌的效应器在感染过程中发挥着至关重要的作用。然而，Ciboriia shiraiana（桑树菌核病的主要病原体）的关键效应子仍然知之甚少。在本研究中，我们鉴定了 C. shiraiana 中的效应子 Cs02526 并进行了功能表征，发现 Cs02526 可以诱导多种植物的细胞死亡。此外，Cs02526 诱导的细胞死亡是由中枢免疫调节剂油菜素类固醇不敏感 1 相关受体激酶 1 (BAK1) 介导的，依赖于 67 个氨基酸片段。值得注意的是，Cs02526同源物广泛分布于半生物营养型和坏死营养型植物病原真菌中，但同源物未能诱导植物细胞死亡。用重组 Cs02526 蛋白预处理植物增强了对 C. shiraiana 和核盘菌的抗性。此外，用合成的 dsRNA-Cs02526 喷洒植物后，C. shiraiana 的致病性减弱。总之，我们的研究结果强调细胞死亡诱导效应子 Cs02526 作为未来植物病害生物防治策略的潜在靶标。