Engineering Technological Center of Fungus Active Substances of Fujian Province, College of Biological Sciences and Technology, Minnan Normal University, Zhangzhou, 363000, China.
Biotechnol Lett. 2024 Dec;46(6):1121-1131. doi: 10.1007/s10529-024-03515-x. Epub 2024 Jul 31.
Rpd3L is a highly conserved histone deacetylase complex in eukaryotic cells and participates in various cellular processes. However, the roles of the Rpd3L component in filamentous fungi remain to be delineated ultimately. In this study, we constructed two knockout mutants of Rpd3L's Rxt3 subunit and characterized their biological functions in A. oryzae. Phenotypic analysis showed that AoRxt3 played a positive role in hyphal growth and conidia formation. Deletion of Aorxt3 resulted in augmented tolerance to multiple stresses, including cell wall stress, cell membrane stress, endoplasmic reticulum stress, osmotic stress and oxidative stress. Noteworthily, we found that Aorxt3-deleting mutants showed a higher kojic acid production than the control strain. However, the loss of Aorxt3 led to a significant decrease in amylase synthesis. Our findings lay the foundation for further exploring the role of other Rpd3L subunits and provide a new strategy to improve kojic acid production in A. oryzae.
Rpd3L 是真核细胞中高度保守的组蛋白去乙酰化酶复合物，参与多种细胞过程。然而，Rpd3L 组件在丝状真菌中的作用仍有待最终阐明。在这项研究中，我们构建了 Rpd3L 的 Rxt3 亚基的两个敲除突变体，并在 A.oryzae 中表征了它们的生物学功能。表型分析表明，AoRxt3 在菌丝生长和分生孢子形成中发挥积极作用。Aorxt3 的缺失导致对多种应激的耐受性增强，包括细胞壁应激、细胞膜应激、内质网应激、渗透应激和氧化应激。值得注意的是，我们发现 Aorxt3 缺失突变体的曲酸产量高于对照菌株。然而，Aorxt3 的缺失导致淀粉酶合成显著减少。我们的发现为进一步探索其他 Rpd3L 亚基的作用奠定了基础，并为提高 A.oryzae 中的曲酸产量提供了新的策略。
