Wang Youyou, Zhang Congying, Liang Jiao, Wang Le, Gao Wenbin, Jiang Jizhi, Chang Ruixue
College of Life Science, Hebei University, Baoding, China.
Hebei Jiuxin Testing Technology Co., Ltd., Baoding, China.
Appl Microbiol Biotechnol. 2020 Sep;104(17):7467-7481. doi: 10.1007/s00253-020-10773-y. Epub 2020 Jul 21.
Potato late blight caused by Phytophthora infestans is one of the most serious plant diseases worldwide. Cyclic lipopeptides (CLPs) extracted from Bacillus strains exhibit a promising effect in the biocontrol of a variety of phytopathogens. However, the specific inhibitory effects and underlying mechanisms of CLPs against P. infestans are poorly understood. In this study, we showed that Bacillus pumilus W-7 can inhibit the growth of P. infestans mycelium. Two metabolites from W-7, surfactin and fengycin B, were identified using MS/MS. Fengycin B inhibited mycelium growth by inducing mycelium deformations, oxidative damage, and mitochondrial dysfunction. Surfactin induced potato plant defense responses by increasing the expression of the biocontrol genes (pod, pal, and cat) and their enzyme activities (POD, PAL, and CAT). Also, surfactin and fengycin B could exhibit a synergistic inhibitory effect on P. infestans. Taken together, our findings indicate that B. pumilus W-7 and its CLPs are potential environmentally friendly and effective biocontrol agents for the preservation of potato crops. KEY POINTS: • Lipopeptides of surfactin and fengycin B are extracted from Bacillus pumilus W-7. • Fengycin B inhibits Phytophthora infestans mycelium growth in a direct manner. • Surfactin induces potato plant defense responses to control late blight.
由致病疫霉引起的马铃薯晚疫病是全球最严重的植物病害之一。从芽孢杆菌菌株中提取的环脂肽（CLPs）在多种植物病原菌的生物防治中显示出有前景的效果。然而，环脂肽对致病疫霉的具体抑制作用和潜在机制尚不清楚。在本研究中，我们表明短小芽孢杆菌W-7能够抑制致病疫霉菌丝体的生长。利用串联质谱法鉴定出W-7产生的两种代谢产物，即表面活性素和丰原素B。丰原素B通过诱导菌丝体变形、氧化损伤和线粒体功能障碍来抑制菌丝体生长。表面活性素通过增加生物防治相关基因（pod、pal和cat）的表达及其酶活性（POD、PAL和CAT）来诱导马铃薯植株的防御反应。此外，表面活性素和丰原素B对致病疫霉可表现出协同抑制作用。综上所述，我们的研究结果表明短小芽孢杆菌W-7及其环脂肽是用于保护马铃薯作物的潜在环境友好且有效的生物防治剂。要点：• 从短小芽孢杆菌W-7中提取出表面活性素和丰原素B的脂肽。• 丰原素B直接抑制致病疫霉的菌丝体生长。• 表面活性素诱导马铃薯植株的防御反应以防治晚疫病。
