Peng Yuejin, Wen Shaohai, Wang Guang, Zhang Xu, Di Teng, Du Guangzu, Chen Bin, Zhang Limin
Yunnan State Key Laboratory of Conservation and Utilization of Biological Resources, College of Plant Protection, Yunnan Agricultural University, Kunming 650201, China.
J Fungi (Basel). 2023 Sep 6;9(9):906. doi: 10.3390/jof9090906.
(Lepidoptera: Noctuidae) is a migratory agricultural pest that is devastating on a global scale. is a filamentous entomopathogenic fungus that has a strong pathogenic effect on Lepidoptera pests but little is known about the microbial community in the host gut and the dominant populations in fungus-infected insects. AJS91881 was isolated and identified from the infected larvae of . The virulence of AJS91881 to the eggs, larvae, pupae and adults of was measured. Moreover, the gut microbial community diversity of healthy and fungus-infected insects was analyzed. Our results showed that after treatment with AJS91881, the egg hatching rate, larval survival rate and adult lifespan of the insects were significantly reduced, and the pupae rigor rate was significantly increased compared to that of the control group. Additionally, the gut microbial community was reconstructed after infection. At the phylum and genus level, the relative abundance of the Proteobacteria and increased significantly in the treatment group. The KEGG function prediction results showed that fungal infection affected insect gut metabolism, environmental information processing, genetic information processing, organism systems and cellular processes. Fungal infection was closely related to the metabolism of various substances in the insect gut. was the bacterium with the highest relative abundance after infection by ; intestinal bacteria inhibited the infection of insect fungi against the . The presence of gut bacteria also significantly reduced the virulence of the fungi against the insects when compared to the group with the larvae fed antibiotics that were infected with fungal suspension (Germfree, GF) and healthy larvae that were infected with fungal suspension prepared with an antibiotic solution (+antibiotic). In conclusion, the reconstruction of the insect intestinal bacterial community is an indispensable link for understanding the pathogenicity of against . . Most importantly, in the later stage of fungal infection, the increased abundance of in the insect intestine inhibited the virulence of to some extent. The findings aid in understanding changes in the gut microbiota during the early stages of entomopathogenic fungal infection of insects and the involvement of insect gut microbes in host defense mediated by pathogenic fungal infection. This study is also conducive to understanding the interaction between entomopathogenic fungi, hosts and gut microbes, and provides a new idea for the joint use of entomopathogenic fungi and gut bacteria to control pests.
（鳞翅目：夜蛾科）是一种具有迁徙性的农业害虫，在全球范围内造成严重破坏。[某种真菌名称]是一种丝状昆虫病原真菌，对鳞翅目害虫具有很强的致病作用，但对宿主肠道中的微生物群落以及真菌感染昆虫后的优势种群了解甚少。从[某种昆虫名称]的感染幼虫中分离并鉴定出AJS91881。测定了AJS91881对[某种昆虫名称]的卵、幼虫、蛹和成虫的毒力。此外，还分析了健康和真菌感染昆虫的肠道微生物群落多样性。我们的结果表明，用AJS91881处理后，与对照组相比，昆虫的卵孵化率、幼虫存活率和成虫寿命显著降低，蛹僵化率显著提高。此外，真菌感染后肠道微生物群落发生了重构。在门和属水平上，变形菌门和[某种菌属名称]在[某种昆虫名称]处理组中的相对丰度显著增加。KEGG功能预测结果表明，真菌感染影响昆虫肠道代谢、环境信息处理、遗传信息处理、生物系统和细胞过程。真菌感染与昆虫肠道中各种物质的代谢密切相关。[某种菌属名称]是[某种昆虫名称]感染后相对丰度最高的细菌；肠道细菌[某种细菌名称]抑制昆虫真菌[某种真菌名称]对[某种昆虫名称]的感染。与喂食抗生素后感染真菌悬液的幼虫组（无菌，GF）和用抗生素溶液制备的真菌悬液感染的健康幼虫组（+抗生素）相比，肠道细菌的存在也显著降低了真菌对昆虫的毒力。总之，昆虫肠道细菌群落的重构是理解[某种真菌名称]对[某种昆虫名称]致病性的不可或缺的环节。最重要的是，在真菌感染后期，昆虫肠道中[某种菌属名称]丰度的增加在一定程度上抑制了[某种真菌名称]的毒力。这些发现有助于了解昆虫病原真菌感染昆虫早期阶段肠道微生物群的变化以及昆虫肠道微生物在病原真菌感染介导的宿主防御中的作用。本研究也有助于理解昆虫病原真菌、宿主和肠道微生物之间的相互作用，并为联合使用昆虫病原真菌和肠道细菌控制害虫提供了新思路。
