Microbial　antibiotic　resistance　has　become　a　worldwide　concern,　as　it　weakens　the　efficiency　of　the　control　of　pathogenic　microbes　in　both　the　fields　of　medicine　and　plant　protection.　A　better　understanding　of　antibiotic　resistance　mechanisms　is　helpful　for　the　development　of　efficient　approaches　to　settle　this　issue.　In　the　present　study,　GC-MS-based　metabolomic　analysis　was　applied　to　explore　the　mechanisms　of　Zhongshengmycin　(ZSM)　resistance　in　Xanthomonas　oryzae　(Xoo),　a　bacterium　that　causes　serious　disease　in　rice.　Our　results　show　that　the　decline　in　the　pyruvate　cycle　(the　P　cycle)　was　a　feature　for　ZSM　resistance　in　the　metabolome　of　ZSM-resistant　strain　(Xoo-ZSM),　which　was　further　demonstrated　as　the　expression　level　of　genes　involved　in　the　P　cycle　and　two　enzyme　activities　were　reduced.　On　the　other　hand,　alanine　was　considered　a　crucial　metabolite　as　it　was　significantly　decreased　in　Xoo-ZSM.　Exogenous　alanine　promoted　the　P　cycle　and　enhanced　the　ZSM-mediated　killing　efficiency　in　Xoo-ZSM.　Our　study　highlights　that　the　depressed　P　cycle　is　a　feature　in　Xoo-ZSM　for　the　first　time.　Additionally,　exogenous　alanine　is　a　candidate　enhancer　and　can　be　applied　with　ZSM　to　improve　the　antibiotic-mediated　killing　efficiency　in　the　control　of　infection　caused　by　Xoo.