The chromatin modulator Set5 plays important regulatory roles in both cell growth and stress responses of Saccharomyces cerevisiae. However, its function in filamentous fungi remains poorly understood. Here, we report the pathogenicity-related gene CgSET5 discovered in a T-DNA insertional mutant M285 of Colletotrichum gloeosporioides. Bioinformatic analysis revealed that CgSET5 encodes a SET domain-containing protein that is a homolog of the budding yeast S. cerevisiae Set5. CgSET5 is important for hyphae growth and conidiation and is necessary for appressorium formation and pathogenicity. CgSet5 regulates appressorium formation in a mitogen-activated protein kinase-independent manner. Inactivation of CgSET5 resulted in a significant reduction in chitin content within the cell wall, indicating CgSet5 plays a vital role in cell wall integrity. CgSet5 is involved in peroxisome biogenesis. We identified CgSet5 as the histone H4 methyltransferase, which methylates the critical H4 lysine residues 5 and 8 in C. gloeosporioides. We carried out a yeast two-hybrid screen to find CgSet5 interacting partners. We found CgSet5 putatively interacts with an inorganic pyrophosphatase named CgPpa1, which co-localized in the cytoplasm with CgSet5. Finally, CgPpa1 was found to strongly interact with CgSet5 in vivo during appressorium formation by bimolecular fluorescence complementation assays. These data corroborate a complex control function of CgSet5 acting as a core pathogenic regulator, which connects cell wall integrity and peroxisome biogenesis in C. gloeosporioides.

染色质调节剂 Set5 在酿酒酵母的细胞生长和应激反应中起着重要的调节作用。然而，其在丝状真菌中的功能仍然知之甚少。在这里，我们报告了在胶孢炭疽菌的 T-DNA 插入突变体 M285 中发现的致病性相关基因CgSET5。生物信息学分析表明，CgSET5编码一个包含 SET 结构域的蛋白质，该蛋白质是出芽酵母酿酒酵母Set5的同源物。设置5对菌丝生长和分生孢子形成很重要，并且是附着菌形成和致病性所必需的。CgSet5 以一种不依赖丝裂原活化蛋白激酶的方式调节附着胞的形成。CgSET5 的失活导致细胞壁内几丁质含量显着减少，表明 CgSet5 在细胞壁完整性中起着至关重要的作用。CgSet5 参与过氧化物酶体生物发生。我们将 CgSet5 鉴定为组蛋白 H4 甲基转移酶，其甲基化C. gloeosporioides 中的关键 H4 赖氨酸残基 5 和 8. 我们进行了酵母双杂交筛选以寻找 CgSet5 相互作用的伙伴。我们发现 CgSet5 可能与名为 CgPpa1 的无机焦磷酸酶相互作用，后者与 CgSet5 共定位于细胞质中。最后，通过双分子荧光互补测定发现 CgPpa1在附着胞形成过程中与体内CgSet5强烈相互作用。这些数据证实了 CgSet5 作为核心致病调节剂的复杂控制功能，它将细胞壁完整性和C. gloeosporioides 中的过氧化物酶体生物发生联系起来。