Microbiome composition of soil, corn (Zea mays) rhizosphere, and western corn rootworm (Diabrotica virgifera virgifera) larvae from cover crop fields

Planting cover crops is an increasingly prevalent sustainable management technique that can increase soil health by increasing microbial abundance and diversity. These soil microbes can improve plant health and alter plant defenses against insects but less is known how the soil microbiome affects insect pest fitness and microbiome composition. The western corn rootworm (WCR) is a major belowground pest of corn throughout the US Corn Belt. Management relies heavily on the planting of transgenic crops expressing Bacillus thuringiensis (Bt). In this study, we ask how does the soil microbiome impact western corn rootworm fitness, microbiome composition, and transgenic crop effectiveness. To do this, we applied soil microbes from continuously managed cover crop fields and those from traditionally managed fields to Bt and non-Bt corn seedlings. We then reared Bt-resistant and -susceptible WCR for 5 days on treated seedlings. Using 16S sequencing, we characterized bacterial communities of the soil, Bt and non-Bt corn rhizospheres, and Bt-resistant WCR larvae.

播种覆盖作物已成为一种日益盛行的可持续管理策略，该策略能够通过提升微生物丰度和多样性来增强土壤健康。这些土壤微生物不仅能够改善植物健康，还能改变植物对昆虫的防御机制，然而关于土壤微生物群对昆虫害虫适应性及微生物群组成的影响，所知甚少。西部玉米根腐虫（WCR）是美国玉米带玉米的主要地下害虫。其管理主要依赖于种植表达苏云金芽孢杆菌（Bt）转基因作物。在本研究中，我们旨在探讨土壤微生物群如何影响西部玉米根腐虫的适应性、微生物群组成以及转基因作物的有效性。为此，我们将连续管理覆盖作物田和传统管理田中的土壤微生物应用于Bt和非Bt玉米幼苗。随后，在处理过的幼苗上饲养了5天的Bt抗性和敏感性西部玉米根腐虫。利用16S测序技术，我们对土壤、Bt和非Bt玉米根际以及Bt抗性西部玉米根腐虫幼虫的细菌群落进行了表征。