浙江农业学报 ›› 2026, Vol. 38 ›› Issue (8): 1628-1635.DOI: 10.3969/j.issn.1004-1524.20250661

• 植物保护 • 上一篇    下一篇

青花菜菌核病拮抗菌XL-09的鉴定与全基因组序列分析

韦海忠1(), 潘丽芹1, 赵文萱2, 李亚楠2, 张慧娟2, 蒋明2,*()   

  1. 1 台州科技职业学院 农业与生物工程学院, 浙江 台州 318020
    2 台州学院 生命科学学院, 浙江 台州 318000
  • 收稿日期:2025-10-20 出版日期:2026-08-25 发布日期:2026-09-14
  • 作者简介:韦海忠,研究方向为植物生理生化。E-mail: hzwei910@126.com
  • 通讯作者: *蒋明,E-mail: jiangming1973@139.com
  • 基金资助:
    台州市科技计划项目(23nya07)

Identification and whole-genome sequence analysis of antagonistic bacterium XL-09 against Sclerotinia sclerotiorum in broccoli

WEI Haizhong1(), PAN Liqin1, ZHAO Wenxuan2, LI Yanan2, ZHANG Huijuan2, JIANG Ming2,*()   

  1. 1 College of Agriculture and Bioengineering, Taizhou Vocational College of Science and Technology, Taizhou 318020, Zhejiang, China
    2 School of Life Sciences, Taizhou University, Taizhou 318000, Zhejiang, China
  • Received:2025-10-20 Published:2026-08-25 Online:2026-09-14

摘要:

核盘菌(Sclerotinia sclerotiorum)是引起菌核病的重要病原真菌,对青花菜(Brassica oleracea var. italica)生产造成严重危害。本研究以先前从青花菜叶片分离得到的内生细菌菌株XL-09为材料,通过形态学观察、生理生化特性测定及分子鉴定,明确其分类地位;采用平板对峙法和离体叶片接种法,评估该细菌对菌核病的抗性作用;并在基因组组装基础上,分析其次生代谢基因簇的组成。结果表明,XL-09菌株在LB固体培养基上菌落呈乳白色,革兰氏染色阳性,能利用D-木糖、蔗糖和L-阿拉伯糖等碳源,接触酶、硝酸盐还原和V-P反应等均为阳性。基于gyrA基因序列构建的系统发育树显示,XL-09与枯草芽孢杆菌(Bacillus subtilis)聚为一组。综合形态学、生理生化及分子鉴定结果,将该菌株鉴定为枯草芽孢杆菌。XL-09对核盘菌生长具有显著拮抗作用,处理后菌落直径明显小于对照,菌核数量显著减少;经XL-09处理的青花菜叶片在接种核盘菌后,病斑显著小于对照。基因组组装结果显示,XL-09基因组全长为4.28 Mb,含有4 525个基因,其中蛋白质编码基因4 308个;共检测到9种次生代谢产物基因簇,涉及产孢致死因子、表面活性素和芽孢杆菌素等的合成。拮抗细菌XL-09的鉴定及全基因组序列分析,为后续抗病机理研究和生物防治应用奠定了基础。

关键词: 核盘菌, 枯草芽孢杆菌, 青花菜, 拮抗作用, 基因组

Abstract:

Sclerotinia sclerotiorum is an important pathogenic fungus causing Sclerotinia disease, which poses serious threats to the production of broccoli (Brassica oleracea var. italica). In this study, an endophytic bacterial strain XL-09 previously isolated from broccoli leaves was used as material. Its taxonomic status was determined through morphological observation, physiological and biochemical characterization, and molecular identification. The antagonistic effect of this bacterium against Sclerotinia disease was evaluated using plate confrontation and detached leaf inoculation methods. Furthermore, based on genome assembly, the composition of secondary metabolite gene clusters was analyzed. The results showed that strain XL09 formed creamy white colonies on LB solid medium, was Grampositive, and could utilize D-xylose, sucrose, and L-arabinose as carbon sources. It was positive for catalase, nitrate reduction, and Voges-Proskauer reaction. Phylogenetic analysis based on gyrA gene sequences revealed that XL09 clustered with Bacillus subtilis. Combining morphological, physiological, biochemical, and molecular identification results, the strain was identified as Bacillus subtilis. XL09 exhibited significant antagonistic activity against the growth of Sclerotinia sclerotiorum, with colony diameter significantly smaller than that of the control and the number of sclerotia markedly reduced. Moreover, broccoli leaves treated with XL09 developed significantly smaller lesions after inoculation with S. sclerotiorum compared to the control. Genome assembly revealed that the complete genome of XL09 is 4.28 Mb in length, containing 4 525 genes, of which 4 308 are protein-coding genes. A total of nine secondary metabolite gene clusters were detected, involved in the synthesis of sporulation lethal factor, surfactin, and bacillocin, among others. The identification and whole genome sequence analysis of antagonistic bacterium XL09 lay a foundation for future studies on disease resistance mechanisms and biocontrol applications.

Key words: Sclerotinia sclerotiorum, Bacillus subtilis, broccoli, antagonism, genome

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