Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China.
Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, China.
Pest Manag Sci. 2023 Aug;79(8):2762-2779. doi: 10.1002/ps.7452. Epub 2023 Mar 23.
The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) can infest over 300 plant species and cause huge economic losses. Beauveria bassiana (Hypocreales: Clavicipitaceae) is one of the most widely used entomopathogenic fungi (EPF). Unfortunately, the efficacy of B. bassiana against S. frugiperda is quite low. Hypervirulent EPF isolates can be obtained by ultraviolet (UV)-irradiation. Here we report on the UV-induced mutagenesis and transcriptomic analysis of B. bassiana.
The wild-type (WT) B. bassiana (ARSEF2860) was exposed to UV light to induce mutagenesis. Two mutants (named 6M and 8M) showed higher growth rates, conidial yields, and germination rates compared to the WT strain. The mutants showed higher levels of tolerance to osmotic, oxidative, and UV stresses. The mutants showed higher protease, chitinase, cellulose, and chitinase activities than WT. Both WT and mutants were compatible with the insecticides matrine, spinetoram, and chlorantraniliprole, but incompatible with emamectin benzoate. Insect bioassays showed that both mutants were more virulent against S. frugiperda and the greater wax moth Galleria mellonella. Transcriptomic profiles of the WT and mutants were determined by RNA-sequencing. The differentially expressed genes (DEGs) were identified. The gene set enrichment analysis (GSEA), protein-protein interaction (PPI) network, and hub gene analysis revealed virulence-related genes.
Our data demonstrate that UV-irradiation is a very efficient and economical technique to improve the virulence and stress resistance of B. bassiana. Comparative transcriptomic profiles of the mutants provide insights into virulence genes. These results provide new ideas for improving the genetic engineering and field efficacy of EPF. © 2023 Society of Chemical Industry.
秋粘虫（Spodoptera frugiperda）（鳞翅目：夜蛾科）可以侵害 300 多种植物，并造成巨大的经济损失。球孢白僵菌（Hypocreales：Clavicipitaceae）是应用最广泛的昆虫病原真菌（EPF）之一。不幸的是，球孢白僵菌对秋粘虫的功效相当低。通过紫外线（UV）照射可以获得超毒力 EPF 分离株。在这里，我们报告了球孢白僵菌的 UV 诱导诱变和转录组分析。
将野生型（WT）球孢白僵菌（ARSEF2860）暴露于紫外光下以诱导诱变。与 WT 菌株相比，两个突变体（命名为 6M 和 8M）表现出更高的生长速度、产孢量和萌发率。突变体表现出更高的耐渗透压、氧化和 UV 应激能力。突变体表现出更高的蛋白酶、几丁质酶、纤维素和几丁质酶活性。WT 和突变体均与杀虫剂苦参碱、乙基多杀菌素和氯虫苯甲酰胺兼容，但与甲氨基阿维菌素苯甲酸盐不兼容。昆虫生物测定表明，两个突变体对秋粘虫和大蜡螟（Galleria mellonella）的毒力更强。通过 RNA-seq 测定了 WT 和突变体的转录组谱。鉴定了差异表达基因（DEGs）。基因集富集分析（GSEA）、蛋白质-蛋白质相互作用（PPI）网络和枢纽基因分析揭示了与毒力相关的基因。
我们的数据表明，UV 照射是一种非常有效和经济的技术，可以提高球孢白僵菌的毒力和抗应激能力。突变体的比较转录组谱提供了对毒力基因的深入了解。这些结果为提高 EPF 的遗传工程和田间功效提供了新的思路。© 2023 化学工业协会。
