Abstract
BackgroundThe western corn rootworm (WCR) is one of the economically most important pests of maize. A better understanding of microbial communities associated with guts and eggs of the WCR is required in order to develop new pest control strategies, and to assess the potential role of the WCR in the dissemination of microorganisms, e.g., mycotoxin-producing fungi.Methodology/Principal FindingsTotal community (TC) DNA was extracted from maize rhizosphere, WCR eggs, and guts of larvae feeding on maize roots grown in three different soil types. Denaturing gradient gel electrophoresis (DGGE) and sequencing of 16S rRNA gene and ITS fragments, PCR-amplified from TC DNA, were used to investigate the fungal and bacterial communities, respectively. Microorganisms in the WCR gut were not influenced by the soil type. Dominant fungal populations in the gut were affiliated to Fusarium spp., while Wolbachia was the most abundant bacterial genus. Identical ribosomal sequences from gut and egg samples confirmed a transovarial transmission of Wolbachia sp. Betaproteobacterial DGGE indicated a stable association of Herbaspirillum sp. with the WCR gut. Dominant egg-associated microorganisms were the bacterium Wolbachia sp. and the fungus Mortierella gamsii. Conclusion/SignificanceThe soil type-independent composition of the microbial communities in the WCR gut and the dominance of only a few microbial populations suggested either a highly selective environment in the gut lumen or a high abundance of intracellular microorganisms in the gut epithelium. The dominance of Fusarium species in the guts indicated WCR larvae as vectors of mycotoxin-producing fungi. The stable association of Herbaspirillum sp. with WCR gut systems and the absence of corresponding sequences in WCR eggs suggested that this bacterium was postnatally acquired from the environment. The present study provided new insights into the microbial communities associated with larval guts and eggs of the WCR. However, their biological role remains to be explored.
Highlights
The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is one of the economically most important pests of maize (Zea mays L.) in the US and it is an increasing threat to corn-growing areas in Europe [1]
To investigate the influence of the soil type on gut-associated fungi, internal transcribed spacers (ITS) fragments amplified from Total community (TC) DNA extracted from guts of larvae sampled in three different soil types were analyzed by Denaturing gradient gel electrophoresis (DGGE) fingerprinting
The present study provides new insight into the gut microbiome of WCR larvae and WCR egg-associated microorganisms
Summary
The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is one of the economically most important pests of maize (Zea mays L.) in the US and it is an increasing threat to corn-growing areas in Europe [1]. Major yield losses are caused by WCR larvae feeding on root tissues resulting in reduced growth and plant lodging. A deeper insight into the microbiome associated with the gut of the WCR might help to predict the spreading of phytopathogenic microorganisms or mycotoxin producing fungi through WCR larvae feeding on maize roots. A better understanding of microbial communities associated with guts and eggs of the WCR is required in order to develop new pest control strategies, and to assess the potential role of the WCR in the dissemination of microorganisms, e.g., mycotoxinproducing fungi
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have