Zhao Yurong, Xie Xuewen, Li Junhui, Shi Yanxia, Chai Ali, Fan Tengfei, Li Baoju, Li Lei
Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Biology (Basel). 2022 Aug 4;11(8):1172. doi: 10.3390/biology11081172.
Bacterial soft rot, caused by , can infect several economically important horticultural crops. However, the management strategies available to control this disease are limited. Plant-growth-promoting rhizobacteria (PGPR) have been considered to be promising biocontrol agents. With the aim of obtaining a strain suitable for agricultural applications, 161 strains were isolated from the rhizosphere soil of healthy cucumber plants and screened through plate bioassays and greenhouse tests. ZF390 exhibited an eminent control effect against soft rot disease and a broad antagonistic activity spectrum in vitro. Moreover, ZF390 showed good activities of cellulase, protease, and phosphatase and a tolerance of heavy metal. Whole-genome sequencing was performed and annotated to explore the underlying biocontrol mechanisms. Strain ZF390 consists of one 6,193,667 bp circular chromosome and three plasmids. Comparative genome analysis revealed that ZF390 involves ten gene clusters responsible for secondary metabolite antibiotic synthesis, matching its excellent biocontrol activity. Plenty of genes related to plant growth promotion, biofilm formation, and induced systemic resistance were mined to reveal the biocontrol mechanisms that might consist in strain ZF390. Overall, these findings suggest that strain ZF390 could be a potential biocontrol agent in bacterial-soft-rot management, as well as a source of antimicrobial mechanisms for further exploitation.
由[未提及具体病原菌]引起的细菌性软腐病可感染几种具有重要经济价值的园艺作物。然而，现有的控制这种病害的管理策略有限。植物促生根际细菌（PGPR）被认为是有前景的生物防治剂。为了获得适合农业应用的菌株，从健康黄瓜植株的根际土壤中分离出161株菌株，并通过平板生物测定和温室试验进行筛选。ZF390对软腐病表现出显著的防治效果，且在体外具有广泛的拮抗活性谱。此外，ZF390表现出良好的纤维素酶、蛋白酶和磷酸酶活性以及对重金属的耐受性。进行了全基因组测序和注释以探索潜在的生物防治机制。菌株ZF390由一条6,193,667 bp的环状染色体和三个质粒组成。比较基因组分析表明，ZF390涉及十个负责次生代谢物抗生素合成的基因簇，与其优异的生物防治活性相匹配。挖掘了大量与植物生长促进、生物膜形成和诱导系统抗性相关的基因，以揭示可能存在于菌株ZF390中的生物防治机制。总体而言，这些发现表明菌株ZF390可能是细菌性软腐病管理中的一种潜在生物防治剂，也是进一步开发抗菌机制的来源。
