State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Sci Total Environ. 2021 Jun 1;771:144880. doi: 10.1016/j.scitotenv.2020.144880. Epub 2021 Jan 27.
Diet is an important factor in shaping and influencing both an insect's phenotype and gut bacterial community, which commonly establishes diversely symbiotic interactions with the host. Efforts to leverage the connection between diet, insects, and gut microbiome primarily focus on how diet alters insect's phenotype or gut microbial composition and relatively few studies have illuminated the link between the diet-induced insect phenotypic difference and variation of gut microbiota. Mirids bugs, Adelphocoris suturalis, are plant sap-feeding omnivores that sometimes complementarily prey on other insects, like aphids (the dietary regime is referred to hereafter as balanced diet). In this study, we found that an imbalanced diet (exclusive ingestion of aphids) induced significantly higher mortality in A. suturalis (86.66%). Further gut microbial community analysis showed that the dietary difference significantly changed both the abundance and composition of the bug's gut microbiome. Most notably, an abundance of entomopathogenic Serratia bacteria in the A. suturalis gut was positively correlated with the proportion of aphids in A. suturalis diet, and Serratia marcescens was found to transfer into the hemocoels of carnivorous bugs. Injection of S. marcescens to the hemocoels further confirmed its detrimental effect to the bugs. Collectively, our study suggests that the diet-altered variation of gut microbiota may be detrimental to host insect, advancing the knowledge of omnivorous insects' strategy in forage allocation of different foods.
饮食是塑造和影响昆虫表型和肠道细菌群落的重要因素，肠道细菌群落通常与宿主建立多样化的共生关系。利用饮食、昆虫和肠道微生物组之间的联系的努力主要集中在饮食如何改变昆虫的表型或肠道微生物组成上，而很少有研究阐明饮食诱导的昆虫表型差异与肠道微生物群的变化之间的联系。盲蝽科昆虫，A. suturalis，是植物汁液取食的杂食动物，有时会补充捕食其他昆虫，如蚜虫（以下简称均衡饮食）。在这项研究中，我们发现，不平衡的饮食（只摄入蚜虫）会导致 A. suturalis 的死亡率显著升高（86.66%）。进一步的肠道微生物群落分析表明，饮食差异显著改变了昆虫肠道微生物群落的丰度和组成。值得注意的是，A. suturalis 肠道中昆虫病原性的沙雷氏菌数量与 A. suturalis 饮食中蚜虫的比例呈正相关，并且发现沙雷氏菌 marcescens 转移到了肉食性昆虫的血腔中。将 S. marcescens 注射到血腔中进一步证实了它对昆虫的有害影响。总的来说，我们的研究表明，饮食改变的肠道微生物群的变化可能对宿主昆虫有害，这提高了杂食性昆虫在不同食物觅食分配策略的认识。
