Department of Entomology, National Chung-Hsing University, Taichung 402, Taiwan.
Department of Entomology, National Chung-Hsing University, Taichung 402, Taiwan; Department of Computer Science and Engineering, Yuan-Ze University, Tao-Yuan City 32003, Taiwan.
J Invertebr Pathol. 2023 Sep;200:107976. doi: 10.1016/j.jip.2023.107976. Epub 2023 Aug 2.
The gut microflora plays an important role in insect development and physiology. The gut bacterial microbiome of the fall armyworm (FAW), Spodoptera frugiperda, in both cornfield and laboratory-reared populations was investigated using a 16S metagenomic approach. The alpha- and beta-diversity of the cornfield FAW populations varied among sampling sites and were higher than those of the laboratory-reared FAW population, indicating that different diets and environments influence the gut bacterial composition. To better understand the interaction between the microbiome and entomopathogenic fungi (EPF), FAWs from organic and conventionally managed corn fields and from the laboratory-reared colony were inoculated with Beauveria bassiana NCHU-153 (Bb-NCHU-153). A longer median lethal time (LT) was observed in the Bb-NCHU-153-infected cornfield FAW population than in the laboratory-reared FAWs. In terms of the microbiome, three Bb-NCHU-153-infected FAW groups showed different gut bacterial compositions compared to noninfected FAW. Further investigation of the cooccurrence network and linear discriminant analysis (LDA) of effect size (LEfSe) revealed that the enriched bacterial genera, such as Enterococcus, Serratia, Achromobacter, and Tsukamurella, in the gut might play the role of opportunistic pathogens after fungal infection; in contrast, some gut bacteria of Methylobacterium, Marinomonas, Paenochrobactrum, Pseudomonas, Acinetobacter, Delftia, Dietzia, Gordonia, Leucobacter, Paracoccus, and Stenotrophomonas might be probiotics against EPF infection. These results indicated that EPF infection can change the gut bacterial composition and lead to a pathobiome in the FAW and that some bacterial species might protect the FAW from EPF infection. These findings could be applied to the design of pathobiome-inducing biocontrol strategies.
肠道微生物在昆虫发育和生理学中起着重要作用。本研究采用 16S 宏基因组学方法研究了草地贪夜蛾（FAW）在玉米田和实验室饲养种群中的肠道细菌微生物组。玉米田 FAW 种群的α-和β多样性在不同采样地点之间存在差异，且高于实验室饲养 FAW 种群，表明不同的饮食和环境影响肠道细菌组成。为了更好地理解微生物组与昆虫病原真菌（EPF）之间的相互作用，从有机和常规管理的玉米田以及实验室饲养的 FAW 中分离出球孢白僵菌 NCHU-153（Bb-NCHU-153），并对其进行接种。结果发现，Bb-NCHU-153 感染的玉米田 FAW 种群的中位致死时间（LT）长于实验室饲养的 FAW。在微生物组方面，与未感染的 FAW 相比，3 个感染 Bb-NCHU-153 的 FAW 组表现出不同的肠道细菌组成。进一步调查共现网络和线性判别分析（LDA）的效应大小（LEfSe）显示，在真菌感染后，肠道中富集的细菌属，如肠球菌、沙雷氏菌、不动杆菌和越橘属，可能发挥机会致病菌的作用；相反，一些肠道细菌，如甲基杆菌、海洋单胞菌、苍白杆菌、假单胞菌、不动杆菌、德氏菌、迪茨氏菌、戈登氏菌、白杆菌、副球菌和食酸菌，可能是针对 EPF 感染的益生菌。这些结果表明，EPF 感染可以改变 FAW 的肠道细菌组成，导致 FAW 的病理生物组，并表明一些细菌物种可能保护 FAW 免受 EPF 感染。这些发现可应用于致病生物组诱导生物防治策略的设计。
