Provincial Key Laboratory for Transformation and Utilization of Cereal Resource, College of Bioengineering, Henan University of Technology, Zhengzhou, China.
Collaborative Innovation Center for Grain Storage Security in Henan Province, Zhengzhou, China.
PLoS One. 2018 Jun 1;13(6):e0198560. doi: 10.1371/journal.pone.0198560. eCollection 2018.
Fusarium head blight (FHB) mainly caused by F. graminearum, always brings serious damage to wheat production worldwide. In this study, we found that strain LM2303 had strong antagonist activity against F. graminearum and significantly reduced disease severity of FHB with the control efficiency of 72.3% under field conditions. To gain a comprehensive understanding of the biocontrol potential of strain LM2303 against FHB, an integrated approach of genome mining and chemical analysis was employed. The whole genome of strain LM2303 was obtained and analyzed, showing the largest number of genes/gene clusters associated with biocontrol functions as compared with the known biocontrol strains (FZB42, M75, CAU B946). And strain LM2303 was accurately determined as a member of the B. velezensis clade using the phylogenomic analysis of single-copy core genes. Through genome mining, 13 biosynthetic gene clusters(BGCs) encoding secondary metabolites with biocontrol functions were identified, which were further confirmed through chemical analyses such as UHPLC-ESI-MS, including three antifungal metabolites (fengycin B, iturin A, and surfactin A), eight antibacterial metabolites (surfactin A, butirosin, plantazolicin and hydrolyzed plantazolicin, kijanimicin, bacilysin, difficidin, bacillaene A and bacillaene B, 7-o-malonyl macrolactin A and 7-o-succinyl macrolactin A), the siderophore bacillibactin, molybdenum cofactor and teichuronic acid. In addition, genes/gene clusters involved in plant colonization, plant growth promotion and induced systemic resistance were also found and analyzed, along with the corresponding metabolites. Finally, four different mechanisms of strain LM2303 involved in the biocontrol of FHB were putatively obtained. This work provides better insights into a mechanistic understanding of strain LM2303 in control of FHB, reinforcing the higher potential of this strain as a powerful biocontrol strain agent (BCA) for FHB control. The results also provide scientific reference and comparison for other biocontrol strains.
镰刀菌穗腐病（FHB）主要由禾谷镰刀菌引起，给全球小麦生产带来了严重的危害。本研究发现，菌株 LM2303 对禾谷镰刀菌具有很强的拮抗活性，在田间条件下可将病害严重度降低 72.3%。为了全面了解菌株 LM2303 对 FHB 的生防潜力，我们采用了基因组挖掘和化学分析相结合的综合方法。获得并分析了菌株 LM2303 的全基因组，与已知的生防菌株（FZB42、M75、CAU B946）相比，该基因组中与生防功能相关的基因/基因簇数量最多。通过单拷贝核心基因的系统发育分析，准确确定菌株 LM2303 为贝莱斯芽孢杆菌群的成员。通过基因组挖掘，鉴定出 13 个编码具有生防功能的次生代谢物的生物合成基因簇（BGCs），通过 UHPLC-ESI-MS 等化学分析进一步证实，包括 3 种抗真菌代谢物（fengycin B、iturin A 和 surfactin A）、8 种抗细菌代谢物（surfactin A、butirosin、plantazolicin 和 hydrolyzed plantazolicin、kijanimicin、bacilysin、diffi cidin、bacillaene A 和 bacillaene B、7-o-malonyl macrolactin A 和 7-o-succinyl macrolactin A）、铁载体 bacillibactin、钼辅因子和 teichuronic 酸。此外，还发现并分析了与植物定殖、植物生长促进和诱导系统抗性相关的基因/基因簇及其相应的代谢物。最后，推测出菌株 LM2303 参与防治 FHB 的 4 种不同机制。这项工作为深入了解菌株 LM2303 防治 FHB 的机制提供了更好的认识，强化了该菌株作为防治 FHB 的强大生防菌剂（BCA）的潜力。研究结果也为其他生防菌株提供了科学参考和比较。
