Department of Forest Protection, College of Forestry, Northeast Forestry University, Harbin 150040, China.
Department of Forest Protection, College of Forestry, Northeast Forestry University, Harbin 150040, China; Institute of Forest Protection, Heilongjiang Academy of Forestry, Harbin 150081, China.
Fungal Genet Biol. 2022 Jan;158:103637. doi: 10.1016/j.fgb.2021.103637. Epub 2021 Nov 16.
Beauveria bassiana is a well-known entomopathogenic fungus that parasitizes on a variety of insect species. Glucan in the cell wall of B. bassiana plays a crucial role in its structure and growth and is also involved in the activation of the host insect's immune system. Glucan biosynthesis is primarily regulated by glucan synthase, however, it is unclear if the glucan synthase catalytic subunit gene (GluS) affects the growth and virulence of B. bassiana. In this study, we constructed the mutant of the B. bassiana glucan synthase catalytic subunit (ΔGluS) by homologous recombination and observed that glucan synthase knockout affects both spore germination and cell area. Further enzyme-based assays along with gene expression analysis of glucan synthase revealed a significant downregulation in the mutant strains compared to the wild type of B. bassiana. Moreover, the virulence of ΔGluS strains against gypsy moth (Lymantria dispar) showed no significant difference compared to the wild-type strains when injected, while the spraying gypsy moths with the conidia of ΔGluS was significantly more lethal than spraying the conidia of the wild type. Altogether, our study constructed a new, highly efficient B. bassiana mutant that can be used for pest control and provides a readily transferable method for other insect-entomopathogenic interaction studies.
球孢白僵菌是一种广为人知的昆虫病原真菌，可寄生在多种昆虫物种上。细胞壁中的葡聚糖在其结构和生长中起着至关重要的作用，同时也参与了宿主昆虫免疫系统的激活。葡聚糖生物合成主要受葡聚糖合酶调控，但葡聚糖合酶催化亚基基因（GluS）是否影响球孢白僵菌的生长和毒力尚不清楚。在这项研究中，我们通过同源重组构建了球孢白僵菌葡聚糖合酶催化亚基（ΔGluS）的突变体，观察到葡聚糖合酶敲除影响孢子萌发和细胞面积。进一步的酶基测定以及葡聚糖合酶的基因表达分析表明，与野生型球孢白僵菌相比，突变株中的表达显著下调。此外，与野生型菌株相比，ΔGluS 菌株对舞毒蛾（Lymantria dispar）的毒力在注射时没有显著差异，而用突变株的分生孢子喷雾处理舞毒蛾比用野生型的分生孢子喷雾处理更致命。总的来说，我们的研究构建了一种新的、高效的球孢白僵菌突变体，可用于害虫防治，并为其他昆虫-昆虫病原相互作用研究提供了一种易于转化的方法。
