中国农业科学 ›› 2026, Vol. 59 ›› Issue (13): 2853-2866.doi: 10.3864/j.issn.0578-1752.2026.13.008

• 植物保护 • 上一篇    下一篇

芽孢杆菌脂肽靶向减弱青枯雷尔氏菌致病力的生防作用

刘羽凡1,3(), 陈峥2(), 陈德局1, 刘欣1, 肖荣凤1, 王阶平1, 王璕3, 刘波1, 何进3(), 陈梅春1()   

  1. 1 福建省农业科学院资源环境与土壤肥料研究所, 福州 350003
    2 福建省农业科学院植物保护研究所, 福州 350003
    3 华中农业大学农业微生物资源发掘与利用全国重点实验室, 武汉 430000
  • 收稿日期:2026-02-25 接受日期:2026-05-01 出版日期:2026-07-01 发布日期:2026-07-01
  • 通信作者:
    何进,E-mail:
    陈梅春,E-mail:
  • 联系方式: 刘羽凡,E-mail:liuyufan12256@163.com。陈峥,E-mail:acerdestiny@163.com。刘羽凡和陈峥为同等贡献作者。
  • 基金资助:
    国家重点研发计划(2022YFF1000700); 福建省农业科学院优秀科技创新人才专项(YCZX202408)

Biocontrol Mechanism of Bacillus-Derived Lipopeptides Through Targeted Reduction of Pathogenicity in Ralstonia solanacearum

LIU YuFan1,3(), CHEN Zheng2(), CHEN DeJu1, LIU Xin1, XIAO RongFeng1, WANG JiePing1, WANG Xun3, LIU Bo1, HE Jin3(), CHEN MeiChun1()   

  1. 1 Institute of Resources, Environment and Soil Fertilizer, Fujian Academy of Agricultural Sciences, Fuzhou 350003
    2 Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou 350003
    3 National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430000
  • Received:2026-02-25 Accepted:2026-05-01 Published:2026-07-01 Online:2026-07-01

摘要:

【目的】由青枯雷尔氏菌(Ralstonia solanacearum)引起的青枯病是一种破坏性严重的土传病害。芽孢杆菌脂肽具有开发为新型生物农药的潜力,但其能否通过削弱病原菌致病力发挥生防作用尚不明确。论文旨在探究脂肽降低青枯菌致病力的机制,为基于致病力调控的新型生物农药研发提供理论依据。【方法】采用倍比稀释法测定脂肽的最小抑菌浓度(MIC);利用盆栽试验评估脂肽对青枯病的防治效果;利用试剂盒测定番茄防御相关酶活性,包括超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、多酚氧化酶(PPO)、过氧化物酶(POD),以及丙二醛(MDA)和过氧化氢(H2O2)含量;结合扫描电镜、半固体平板运动性试验及转录组测序,系统分析脂肽对青枯菌形态、运动性及基因表达的影响。【结果】芽孢杆菌FJAT-2349脂肽的MIC为0.1875 mg·mL-1,在0.075 mg·mL-1亚抑菌浓度下,番茄青枯病发病率相对于青枯菌对照组降低29.2%;该浓度脂肽未引起番茄叶片SOD、CAT、PPO和POD活性及MDA和H2O2含量的显著变化,表明其未诱导植株系统抗性。电镜观察显示,经脂肽处理的菌体伸长至正常细胞的3倍,提示细胞分裂受阻;运动性能力降低约36%。转录组分析表明,脂肽处理导致青枯菌细胞分裂基因(ZapE)、III型分泌系统调控基因(hrpB1hrpB2)、鞭毛转录调控因子(flhC)、毒力效应蛋白基因表达显著下调,而鞭毛蛋白基因(fliC)、组氨酸利用相关酶基因(hipO)、RNA聚合酶β'亚基基因(rpoC)和细胞分裂相关基因(ftsK)表达显著上调。KEGG富集分析显示,差异表达基因主要集中于代谢(能量代谢、氨基酸代谢以及次生代谢产物生物合成)、遗传信息处理(翻译和RNA加工与代谢)和环境信息处理(ABC蛋白转运)等相关通路,表明脂肽通过干扰能量代谢和物质运输、破坏蛋白质合成与周转,重编程病原菌的代谢活动,进而抑制其生长与繁殖。【结论】亚抑菌浓度芽孢杆菌FJAT-2349脂肽主要通过双重核心机制发挥生防作用:阻滞细胞分裂进程,并抑制III型分泌系统毒力;协同干扰病菌能量代谢和物质运输、破坏蛋白质合成与周转、降低病菌运动能力,从而系统性削弱其致病力。

关键词: 芽孢杆菌, 脂肽, 青枯雷尔氏菌, 致病力, 生物防治

Abstract:

【Objective】Bacterial wilt caused by Ralstonia solanacearum is a highly destructive soil-borne disease. Lipopeptides produced by Bacillus species are promising biocontrol agents. However, whether lipopeptides can exert biocontrol effects by attenuating the pathogenicity of R. solanacearum remains unclear. This study aims to investigate the mechanism by which lipopeptides target and reduce the pathogenicity of R. solanacearum, and to provide a theoretical basis for developing novel biocontrol agents based on pathogenicity regulation.【Method】The minimum inhibitory concentration (MIC) of lipopeptides was determined using the broth dilution method. The control efficacy of lipopeptides against bacterial wilt was evaluated through pot experiments. Defense-related enzyme activities including superoxide dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO), and peroxidase (POD), as well as the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in tomato plants were determined using commercial assay kits. Combined with scanning electron microscopy, semi-solid plate motility test, and transcriptome sequencing, the effects of lipopeptides on the morphology, motility, and gene expression of R. solanacearum were systematically analyzed.【Result】The MIC of lipopeptides from Bacillus sp. FJAT-2349 was 0.1875 mg·mL-1. At a sub-inhibitory concentration (0.075 mg·mL-1), the incidence of tomato bacterial wilt decreased by 29.2% compared to the R. solanacearum control group. No significant changes were observed in the activities of SOD, CAT, PPO, POD, or the contents of MDA and H2O2 in tomato leaves, indicating that this concentration of lipopeptides failed to induce systemic resistance in tomato plants. SEM analysis showed that lipopeptide-treated R. solanacearum cells exhibited an elongated rod-shaped morphology with a length approximately three times that of normal cells, suggesting impaired cell division. Motility assays showed that bacterial movement was reduced by approximately 36%. Transcriptomic analysis revealed significant down-regulation of genes associated with cell division (ZapE), type III secretion system (T3SS) regulation (hrpB1, hrpB2), flagellar transcriptional regulator (flhC) and genes encoding virulence effector proteins. The gene expressions of cell division-related enzyme (ftsK), flagellin (fliC), histidine utilization-related enzyme (hipO), and RNA polymerase β' subunit (rpoC) were up-regulated. KEGG enrichment analysis indicated that differentially expressed genes were significantly enriched in pathways related to metabolism (energy metabolism, amino acid metabolism, and biosynthesis of secondary metabolites), genetic information processing (translation and RNA processing and metabolism), and environmental information processing (ABC protein transport), suggesting that lipopeptide treatment interferes with energy metabolism and substance transport, disrupts protein synthesis and turnover, reprograms the metabolic activity of R. solanacearum, and thereby inhibits its growth and reproduction.【Conclusion】Bacillus sp. FJAT-2349 lipopeptides at sub-inhibitory concentration exert their biocontrol effect primarily through a dual-core mechanism: blocking cell division progression and suppressing T3SS virulence, which synergistically interfere with pathogen energy metabolism and substance transport, disrupt protein synthesis and turnover, and reduce pathogen motility, thereby attenuating the pathogenicity of R. solanacearum.

Key words: Bacillus, lipopeptide, Ralstonia solanacearum, pathogenicity, biocontrol