Qiu Rongrong, Zhou Jinyuan, Cao Tingting, Xia Yuxian, Peng Guoxiong
Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China.
Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China.
J Fungi (Basel). 2025 Aug 27;11(9):628. doi: 10.3390/jof11090628.
Conidiation and stress tolerance are pivotal traits in entomopathogenic fungi, critically influencing their production costs and environmental tolerance. While the transcription factor high-mobility group protein (HMG), characterized by a conserved HMG-box domain, has been extensively studied for its role in sexual development, its functions in entomopathogenic fungi remain largely unexplored. This study employed gene knockout to investigate the role of MaHMG in . The deletion of delayed conidiation initiation and caused a highly significant 58% reduction in conidial yield versus that of the wild type (WT) after 15 days. Furthermore, the conidiation pattern on microcycle induction medium (SYA) shifted from microcycle to normal conidiation. The Δ mutant exhibited decreased conidial germination rates and markedly reduced tolerance following UV-B irradiation and heat-shock treatments, alongside increased sensitivity to the cell wall perturbant calcofluor white (CFW). RNA-seq analysis during this conidiation shift identified 88 differentially expressed genes (DEGs), with functional annotation implicating their predominant association with hyphal development, cell wall biogenesis, cell cycle progression, and conidiation. In conclusion, MaHMG functions as a critical positive regulator governing both conidiation and stress tolerance in , underscoring its fundamental role in fungal biology and potential as a target for enhancing biocontrol agent performance.
产孢和胁迫耐受性是昆虫病原真菌的关键特性，对其生产成本和环境耐受性有至关重要的影响。虽然以保守的HMG-box结构域为特征的转录因子高迁移率族蛋白（HMG）在有性发育中的作用已得到广泛研究，但其在昆虫病原真菌中的功能仍 largely未被探索。本研究采用基因敲除来研究MaHMG在 中的作用。 的缺失延迟了产孢起始，在15天后与野生型（WT）相比，产孢量显著降低了58%。此外，在微周期诱导培养基（SYA）上的产孢模式从微周期产孢转变为正常产孢。Δ突变体的分生孢子萌发率降低，在UV-B照射和热休克处理后的耐受性明显降低，同时对细胞壁扰动剂荧光增白剂（CFW）的敏感性增加。在这种产孢转变过程中的RNA-seq分析鉴定出88个差异表达基因（DEG），功能注释表明它们主要与菌丝发育、细胞壁生物合成、细胞周期进程和产孢相关。总之，MaHMG作为一个关键的正调控因子，在 中调控产孢和胁迫耐受性，突显了其在真菌生物学中的基础作用以及作为提高生物防治剂性能靶点的潜力。
