文献类型：期刊文献

英文题名：Gut bacterium Acinetobacter sp. assists Camellia weevil with host plant adaptation by degrading tea saponin via the benzoate pathway

作者：Song, Feng[1] Shu, Jinping[2] Zhang, Shouke[1]

第一作者：Song, Feng

通信作者：Zhang, SK[1];Shu, JP[2]

机构：[1]Zhejiang A&F Univ, Natl Key Lab Dev & Utilizat Forest Food Resources, Hangzhou 311300, Zhejiang, Peoples R China;[2]Chinese Acad Forestry, Res Inst Subtrop Forestry, Hangzhou 311400, Zhejiang, Peoples R China

年份：2025

卷号：13

期号：1

外文期刊名：MICROBIOME

收录：;Scopus(收录号：2-s2.0-105007745784);WOS:【SCI-EXPANDED(收录号:WOS:001503486400001)】；

基金：This study was funded by the National Natural Science Foundation of China (Grant No. 32201561) and the "Pioneer" and "Leading Goose" R&D Program of Zhejiang (Grant No. 2023 C02034).the "Pioneer" and "Leading Goose" R&D Program of Zhejiang, 2023 C02034, the National Natural Science Foundation of China,32201561

语种：英文

外文关键词：Acinetobacter sp. AS23; Curculio chinensis; Toxic secondary metabolites; CRISPR-Cas9; Benzoate degradation pathway; Tea saponin

摘要：BackgroundThe extent to which herbivorous insects depend on gut bacteria and the molecular mechanisms by which these microbes help overcome host plant chemical defenses remain controversial. This study explored how the gut symbiont Acinetobacter sp. AS23 of a Camellia weevil (Curculio chinensis) (CW) enhances the weevil's tolerance to toxic tea saponins in host plants.MethodsWe first conducted toxicity assays in which third-instar CW larvae were exposed to fermentation filtrates containing tea saponin degradation products from the weevil's gut bacterium, the AS23 strain. A combination of metabolomic and transcriptomic analyses was used to investigate the degradation pathway and key genes used by the AS23 strain in tea saponin metabolism. We then re-inoculated axenic larvae with bacterial mutants generated through CRISPR-Cas9 and verified gene functions in tea saponin degradation.ResultsToxicity assays demonstrated that the AS23 strain exhibited time-dependent tea saponin degradation capabilities. The benzoate degradation pathway emerged as a core metabolic pathway enriched during tea saponin degradation, with the involvement of four key enzyme genes confirmed through qPCR and functional studies. Knockout strains exhibited a significantly reduced detoxification capacity and increased larval mortality when reintroduced into CWs' gut.ConclusionOur findings elucidated the key role of the AS23 strain in mediating CW larvae tolerance to tea saponins through the benzoate degradation pathway. This study highlights the potential of leveraging microbial saponin degradation pathways for developing environmentally friendly pest control strategies.