基于植物代谢组学和昆虫肠道细菌分析光肩星天牛的寄主适应性

为探究光肩星天牛Anoplophora glabripennis对传统抗性树种白蜡的适应性机制，利用代谢组学分析不同白蜡品种木质部次生代谢产物，利用16S rRNA测序技术对取食白蜡后的光肩星天牛肠道细菌群落组成进行检测，并采用Pearson方法分析两者的相关性。结果表明，在洋白蜡Fraxinuspennsylvanica和中国白蜡F. chinensis木质部中共筛选出27类抗虫性差异代谢产物，其中黄酮苷、双黄酮及多黄酮、简单酚类、香豆素及其衍生物和木质素苷在中国白蜡中含量较丰富；而2-芳基苯并呋喃类黄酮、阿朴啡类、麦角林及其衍生物和有机氮化合物在洋白蜡中占优。光肩星天牛取食洋白蜡和中国白蜡2种寄主后肠道细菌群落组成存在明显差异，优势菌门分别为变形菌门和厚壁菌门；优势菌属分别为拉乌尔菌属Raoultella（55.79%）和乳球菌属Lactococcus（57.52%）；筛选到21个差异菌属，其中13个菌属在中国白蜡中的相对丰度显著高于洋白蜡。相关性分析结果表明，尽管类黄酮、简单酚类、香豆素及其衍生物和木质素苷等酚类化合物在中国白蜡中含量更高，但取食中国白蜡后光肩星天牛肠道内一方面存在优势菌群参与代谢上述物质，如肠球菌属Enterococcus、拉乌尔菌属对类黄酮和木质素苷的代谢；另一方面中国白蜡通过一些特异菌属和共有菌属的增殖参与代谢，如乳杆菌属Lacto-bacillus和放线菌属Actinomycetes对类黄酮、乳球菌属对简单酚类、鞘氨醇杆菌属 Sphingobacterium对香豆素及其衍生物、放线菌属和肠球菌属对木质素苷的代谢。生物碱在中国白蜡中的含量低于洋白蜡，未发现特殊菌属降解该类物质。推测相对于洋白蜡，取食中国白蜡后光肩星天牛肠道菌群更具特异性和多样化，可以帮助光肩星天牛快速代谢相关次生物质，顺利完成其在中国白蜡上的生活史。

Host adaptability of Asian longhorn beetle Anoplophora glabripennis based on metabolomics and insect intestinal bacteria

In order to explore the adaptation mechanism of Asian longhorn beetle Anoplophora glabripennis to traditional resistant Fraxinus spp., metabonomic technology was used to analyze secondary metabolites in the xylem of different Fraxinus varieties, and 16S rRNA sequencing technology was used to detect A. glabripennis intestinal bacterial community after fed with above-mentioned plants, and the Pearson method was used to analyze the correlation between plant differential metabolites and insect intestinal bacteria. The results showed that a total of 27 different metabolites were screened out from the xylem of F. pennsylvanica and F. chinensis, among which flavonoid glycosides, biflavonoids and polyflavonoids, simple phenols, coumarins and derivatives, and lignan glycosides were abundant in F. chinensis, while 2-arylbenzofuran flavonoids, aporphines, ergoline and derivatives and organonitrogen compounds were abundant in F. pennsylvanica. After feeding the two host plants, there were significant differences in intestinal bacterial community of A. glabripennis. After feeding F. pennsylvanica and F. chinensis, it was found that the dominant phyla of intestinal bacteria were Proteobacteria and Firmicutes at phylum level, respectively. At genus level, Raoultella (55.79%) and Lactococcus (57.52%) were the most dominant bacteria, respectively. Twenty-one different bacterial genera were screened out, of which 13 had significantly higher relative abundance in F. chinensis. Correlation analysis results showed that, although flavonoids, simple phenols, coumarin and its derivatives, and lignin glycosides were more abundant in F. chinensis, there were dominant bacteria in intestines of A. glabripennis involved in metabolism of these substances, including Enterococcus and Raoultella that could metabolize flavonoids and lignin glycosides. In addition, some specific bacteria emerged or some common bacteria increased after feeding F. chinensis, including Lactobacillus and Actinomycetes that could metabolize flavonoids, Lactococcus that could metabolizes simple phenols, Sphingobacterium that could metabolize coumarin and derivatives, and Actinomycetes and Enterococcus that could metabolize lignin glycosides. Alkaloids in F. chinensis were less abundant, and there were no more special bacteria to degrade them in intestines after feeding F. chinensis. The results indicated that more specific and diversified bacterial community were found in intestines of A. glabripennis after feeding F. chinensis, which were beneficial for rapid metabolization of related secondary substances and completing its life cycle on F. chinensis.