Qin Qunying, Liu Boyu, Ma Baige, Wei Xihong, Zhou Yi, Sun Zhengxiang
College of Agriculture, Yangtze University, Jingzhou 434025, China.
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland, College of Agriculture, Yangtze University, Jingzhou 434025, China.
J Fungi (Basel). 2025 Jun 12;11(6):446. doi: 10.3390/jof11060446.
The fungus , which causes tobacco brown spot disease, poses a serious threat to the tobacco industry. Beneficial microorganisms and their secondary metabolites have emerged as a promising green strategy for disease management. This study recovered 16 endophytic bacterial strains from Briq., a therapeutic herb. The study revealed that strain B5, with an inhibition rate of 82.76%, exhibited the highest antifungal activity against . This strain exhibited broad-spectrum antifungal activity, with inhibition rates ranging from 66.34% to 87.23%. Phylogenetic analysis of 16S rDNA and gene sequences identified it as (GenBank: PV168970 and PV173738). Further characterization revealed that strain B5 can secrete cell wall-degrading enzymes, produce IAA, and synthesize siderophores. The growth of mycelium in was greatly reduced by both the ethyl acetate extract and the filtered liquid from the sterile fermentation, resulting in marked morphological abnormalities. Multiple antifungal active substances were identified through liquid LC-MS analysis. Greenhouse experiments demonstrated that the B5 fermentation broth effectively suppressed the occurrence of tobacco brown spot disease, achieving a relative control efficacy of 60.66%, comparable to that of 10% difenoconazole water dispersible granule (WDG). Additionally, strain B5 enhances plant disease resistance by activating the activities of key defense enzymes. B5 serves as a safe alternative to chemical fungicides and is highly effective at controlling tobacco brown spot disease.
这种引发烟草赤星病的真菌对烟草行业构成了严重威胁。有益微生物及其次生代谢产物已成为一种很有前景的病害治理绿色策略。本研究从一种药用植物毛喉鞘蕊花中分离出16株内生细菌菌株。研究表明，菌株B5对该真菌的抑制率为82.76%，表现出最高的抗真菌活性。该菌株具有广谱抗真菌活性，抑制率在66.34%至87.23%之间。通过对16S rDNA和基因序列的系统发育分析，将其鉴定为解淀粉芽孢杆菌（GenBank：PV168970和PV173738）。进一步的特性分析表明，菌株B5能够分泌细胞壁降解酶、产生吲哚乙酸并合成铁载体。乙酸乙酯提取物和无菌发酵滤液均能显著降低该真菌菌丝体的生长，导致明显的形态异常。通过液相LC-MS分析鉴定出多种抗真菌活性物质。温室试验表明，B5发酵液能有效抑制烟草赤星病的发生，相对防效达60.66%，与10%苯醚甲环唑水分散粒剂相当。此外，菌株B5通过激活关键防御酶的活性来增强植物抗病性。B5可作为化学杀菌剂的安全替代品，对防治烟草赤星病高效。
