College of Plant Protection, Henan Agricultural University, Zhengzhou, 450046, China.
Food Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China.
BMC Microbiol. 2024 Oct 18;24(1):415. doi: 10.1186/s12866-024-03519-7.
Bitter gourd wilt, a severe vascular disease triggered by the soilborne pathogen Fusarium oxysporum f. sp. momordicae (FOM), markedly constrains bitter gourd yield. In this study, a novel strain BF19 of Brevibacillus brevis was isolated and identified, exhibiting strong antimicrobial activity against FOM through in vivo and in vitro experiments. To comprehensively assess the biocontrol potential of strain BF19, we conducted phenotypic, phylogenetic, and comparative genomics analyses. Phenotypic analysis revealed that BF19 exhibited 53.33% biocontrol efficacy and significantly increased the average plant height, root fresh weight, and dry weight. Whole-genome sequencing and comparative genomic analysis revealed numerous potential genes associated with biocontrol mechanisms in BF19. Importantly, the integration of metabolic cluster prediction with liquid chromatography‒tandem mass spectrometry (LC‒MS/MS) revealed the presence of a macrobrevin antibiotic, a product of polyketide synthases (PKSs), predominantly in BF19 fermentation products. The effectiveness of the Br. brevis strain BF19 and its crude extract against bitter gourd wilt has also been confirmed. This study provides a genetic framework for future investigations on PKSs and establishes a scientific basis for optimizing field applications of microbial biopesticides derived from Br. brevis BF19.
苦瓜疫病是一种由土传病原菌尖孢镰刀菌苦瓜专化型（Fusarium oxysporum f. sp. momordicae，FOM）引起的严重维管束病害，严重制约了苦瓜的产量。本研究从苦瓜根际土壤中分离到一株短小芽孢杆菌（Brevibacillus brevis）BF19 菌株，该菌株对 FOM 具有较强的拮抗活性，通过体内和体外实验得到验证。为了全面评估 BF19 菌株的生防潜力，我们进行了表型、系统发育和比较基因组学分析。表型分析表明，BF19 对苦瓜疫病的防治效果达到 53.33%，并显著提高了苦瓜的平均株高、根鲜重和根干重。全基因组测序和比较基因组分析揭示了 BF19 中与生物防治机制相关的大量潜在基因。重要的是，通过代谢簇预测与液相色谱-串联质谱（LC-MS/MS）的结合，发现了一种大环内脂类抗生素，它是聚酮合酶（PKSs）的产物，主要存在于 BF19 的发酵产物中。短小芽孢杆菌 BF19 及其粗提物对苦瓜疫病的防治效果也得到了验证。本研究为进一步研究 PKSs 提供了遗传框架，并为优化短小芽孢杆菌 BF19 衍生的微生物生物农药的田间应用提供了科学依据。
