College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China.
College of Plant Protection, Jilin Agricultural University, Changchun, China.
Mol Plant Pathol. 2024 Feb;25(2):e13429. doi: 10.1111/mpp.13429.
Ustilaginoidea virens is the causal agent of rice false smut, which has recently become one of the most important rice diseases worldwide. Ustilaginoidins, a major type of mycotoxins produced in false smut balls, greatly deteriorates grain quality. Histone acetylation and deacetylation are involved in regulating secondary metabolism in fungi. However, little is yet known on the functions of histone deacetylases (HDACs) in virulence and mycotoxin biosynthesis in U. virens. Here, we characterized the functions of the HDAC UvHOS3 in U. virens. The ΔUvhos3 deletion mutant exhibited the phenotypes of retarded growth, increased mycelial branches and reduced conidiation and virulence. The ΔUvhos3 mutants were more sensitive to sorbitol, sodium dodecyl sulphate and oxidative stress/H O . ΔUvhos3 generated significantly more ustilaginoidins. RNA-Seq and metabolomics analyses also revealed that UvHOS3 is a key negative player in regulating secondary metabolism, especially mycotoxin biosynthesis. Notably, UvHOS3 mediates deacetylation of H3 and H4 at H3K9, H3K18, H3K27 and H4K8 residues. Chromatin immunoprecipitation assays indicated that UvHOS3 regulates mycotoxin biosynthesis, particularly for ustilaginoidin and sorbicillinoid production, by modulating the acetylation level of H3K18. Collectively, this study deepens the understanding of molecular mechanisms of the HDAC UvHOS3 in regulating virulence and mycotoxin biosynthesis in phytopathogenic fungi.
绿僵菌是稻曲病的致病菌，近年来已成为全球最重要的水稻病害之一。假菌核中的主要真菌毒素类毒素——绿僵菌素，严重降低了稻谷的品质。组蛋白乙酰化和去乙酰化参与调控真菌的次生代谢。然而，关于组蛋白去乙酰酶（HDACs）在绿僵菌的毒力和真菌毒素生物合成中的功能，目前还知之甚少。在这里，我们对 HDAC UvHOS3 在绿僵菌中的功能进行了研究。ΔUvhos3 缺失突变体表现出生长迟缓、菌丝分支增多、产孢减少和毒力降低的表型。ΔUvhos3 突变体对山梨醇、十二烷基硫酸钠和氧化应激/H 2 O 2 更为敏感。ΔUvhos3 产生的绿僵菌素明显更多。RNA-Seq 和代谢组学分析还表明，UvHOS3 是调控次生代谢，特别是真菌毒素生物合成的关键负调控因子。值得注意的是，UvHOS3 介导 H3 和 H4 在 H3K9、H3K18、H3K27 和 H4K8 残基上的去乙酰化。染色质免疫沉淀试验表明，UvHOS3 通过调节 H3K18 的乙酰化水平来调控真菌毒素生物合成，特别是绿僵菌素和索氏菌素的产生。总之，这项研究加深了我们对 HDAC UvHOS3 调节植物病原真菌毒力和真菌毒素生物合成的分子机制的理解。
