Functional Role of Intestinal Symbiotic Microorganisms in Improving the Adaptability of Anoplophora glabripennis to Resistant Host Plants

Abstract

To investigate the adaptation mechanism of Anoplophora glabripennis to traditional resistant Fraxinus, we used metabolomics, enzyme activity detection, and 16SrRNA sequencing technology to analyze the correlation among plants, insects, and symbiotic microorganisms. The results show that a total of 19 classes and 108 different resistant metabolites were screened from xylem of Fraxinus pennsylvanica and Fraxinus chinensis. Except iridoids, lignin, alkaloids, and derivatives; amines, cinnamic acids, and derivatives; and amino acids and derivatives, the rest of them were abundant in F. chinensis. The activity of digestive enzymes and detoxifying enzymes in the intestinal of F. pennsylvanica feeder was significantly higher than that of F. chinensis feeder. After feeding on two hosts, there were significant differences in the intestinal bacterial community of A. glabripennis. At the phylum level, the dominant phyla of intestinal bacteria after feeding on F. pennsylvanica and F. chinensis were Proteobacteria and Firmicutes, respectively. At the genus level, Raoultella (55.79%) and Lactococcus (57.52%) were the most dominant bacteria, respectively. The correlation analysis shows that β-glucosidase, exo-β-1,4-glucanase, lipase, carboxylesterase, and cytochrome P450 had a significant negative correlation with sesquiterpenoids, amino acids, and derivatives, and a significant positive correlation with lignin and amines. Raoultella, unclassified Enterobactriaceae, and Enterobacter in the gut community were negatively correlated with sesquiterpenes and amino acid derivatives and significantly positively correlated with lignin and amines. The correlations with defensive substances for Lactococcus, Enterococcus, and Gibbsiella were the exact opposite of those for these gut communities. This can provide a new idea for the prevention and control of A. glabripennis by studying the interaction among plants, insects and intestinal symbiotic microorganisms.