Bai Jianyang, Xu Zhe, Li Lu, Zhang Yue, Diao Jian, Cao Jingyu, Xu Letian, Ma Ling
Department of Forest Protection, College of Forestry, Northeast Forestry University, Harbin 150040, China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China.
Department of Forest Protection, College of Forestry, Northeast Forestry University, Harbin 150040, China.
J Invertebr Pathol. 2023 Mar;197:107897. doi: 10.1016/j.jip.2023.107897. Epub 2023 Feb 15.
The gut bacterial microbiota of insects has been shown to play essential roles in processes related to physiology, metabolism, and innate immunity. In this study, we firstly performed a broad analysis of the gut bacteria in Lymantria dispar asiatica, one of the most devastating forestry defoliators. We analyzed the bacterial composition among different individuals from lab-reared or wild-collected using 16 s rRNA-sequencing, revealing that the gut bacteria of wild-collected larvae were highly diverse, while lab-reared larvae were only associated with a few genera. We found Lactobacillus sp. present in all the gut samples, which indicates that it is part of the core microbiome in the caterpillar. Further Beauveria bassiana infection-based assays showed that the mortality of non-axenic L. dispar asiatica larvae was significantly higher than that of axenic larvae at 72 h. Moreover, we isolated several bacteria from the hemolymph of the non-axenic larvae infected by B. bassiana, which may be caused by the translocation of gut bacteria from the gut to the hemocoel. Reintroduction of Enterococcus sp., Pseudomonas sp., Enterobacter sp., and Microbacterium sp. into axenic larvae recurred the larval mortality in their non-axenic counterpart. Taken together, our study demonstrates that the gut bacteria of L. dispar asiatica are highly volatile, and different bacteria taxa can promote host infection by entomopathogenic fungus, providing a new strategy for the pest management.
昆虫的肠道细菌微生物群已被证明在与生理、代谢和先天免疫相关的过程中发挥着重要作用。在本研究中，我们首先对亚洲舞毒蛾（最具破坏性的林业食叶害虫之一）的肠道细菌进行了广泛分析。我们使用16S rRNA测序分析了实验室饲养或野外采集的不同个体之间的细菌组成，发现野外采集幼虫的肠道细菌高度多样，而实验室饲养的幼虫仅与少数几个属相关。我们发现所有肠道样本中都存在乳酸杆菌属，这表明它是毛虫核心微生物群的一部分。进一步基于球孢白僵菌感染的试验表明，在72小时时，非无菌亚洲舞毒蛾幼虫的死亡率显著高于无菌幼虫。此外，我们从感染球孢白僵菌的非无菌幼虫的血淋巴中分离出几种细菌，这可能是由于肠道细菌从肠道转移到血腔所致。将肠球菌属、假单胞菌属、肠杆菌属和微杆菌属重新引入无菌幼虫中，其幼虫死亡率与非无菌幼虫相当。综上所述，我们的研究表明亚洲舞毒蛾的肠道细菌高度不稳定，不同的细菌类群可以促进昆虫病原真菌对宿主的感染，为害虫管理提供了一种新策略。
