MoMkt1, a member of XPG/RAD2 nuclease family, regulates development and pathogenicity in Magnaporthe oryzae

XPG/RAD2 nuclease family plays a crucial role in DNA damage repair to maintain genomic integrity. However, the biological function Mkt1, a member of XPG/RAD2 nuclease family, is still unclear in M. oryzae. Here, we identified and characterized the biological functions of MoMkt1. Our results demonstrated that MoMkt1 is involved in hyphal growth, conidiation, normal appressorium development, degradation of glycogen and lipid droplets, responses to cell wall stress and pathogenicity in M. oryzae. Additionally, MoMkt1 is required for scavenging host-derived ROS and response to DNA replicative stress. Further investigation revealed that MoMkt1 interacts with the TFIIH core subunit MoTfb2. Overexpression of MoTFB2 slightly affected virulence of M. oryzae. Transcriptome data revealed that MoMKT1 regulates metabolic pathways, cell wall, oxidation-reduction process and DNA repair. Our study provides insights into the MoMkt1-mediated development and pathogenicity in M. oryzae.XPG/RAD2核酸酶家族（XPG/RAD2 nuclease family）在DNA损伤修复过程中发挥关键作用，以维持基因组完整性。然而，作为XPG/RAD2核酸酶家族成员的Mkt1，其在稻瘟病菌（Magnaporthe oryzae，简称M. oryzae）中的生物学功能仍未明确。本研究对稻瘟病菌中的MoMkt1进行了鉴定，并系统表征了其生物学功能。研究结果显示，MoMkt1参与调控稻瘟病菌的菌丝生长、产孢、正常附着胞（appressorium）发育、糖原与脂滴降解、细胞壁应激响应以及致病力。此外，MoMkt1对于清除宿主源性活性氧（reactive oxygen species，ROS）以及应对DNA复制应激不可或缺。进一步的互作分析表明，MoMkt1可与通用转录因子IIH（transcription factor II H，TFIIH）核心亚基MoTfb2发生相互作用。过表达MoTFB2会轻度影响稻瘟病菌的致病力。转录组数据显示，MoMKT1可调控代谢通路、细胞壁相关过程、氧化还原过程以及DNA修复通路。本研究为解析稻瘟病菌中MoMkt1介导的生长发育与致病机制提供了重要见解。