Han Jian, Shi Meili, Dou Xinyu, Pan Wen, Ma Deying, Luo Ming, Fu Benzhong
Department of Plant Pathology, College of Agronomy, Xinjiang Agricultural University, Urumqi, China.
Key Laboratory of Prevention and Control of Invasive Alien Species in Agriculture and Forestry of the North-western Desert Oasis (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Urumqi, China.
Front Microbiol. 2025 Mar 12;16:1555523. doi: 10.3389/fmicb.2025.1555523. eCollection 2025.
Verticillium wilt of cotton, caused by , is one of the most devastating soilborne fungal diseases in cotton production, urgently demanding the development of effective control measures. Myxobacteria, a group of higher prokaryotes exhibiting multicellular social behaviors, possess predatory activity against plant pathogenic fungi and bacteria, giving them unique potential for application in plant disease biocontrol. In this study, based on a previously myxobacterial strain collection, a myxobacterial strain, HM-E, exhibiting broad-spectrum antifungal activity was screened. Through morphological observation, physiological and biochemical characterization, and multi-locus sequence analysis, this strain was identified as HM-E. HM-E not only significantly lysed hyphae but also inhibited its spore germination. Both its cell-free fermentation filtrate and volatile metabolites exhibited certain antifungal activity. Greenhouse pot assays showed that the fermentation broth of HM-E had a control efficacy of only 23.01% against cotton Verticillium wilt, whereas the solid agent formulated with white star flower chafer () frass achieved a significantly higher control efficacy of 70.90%, and the myxobacterial solid agent also significantly promoted cotton seedling growth. Furthermore, the crude extracts concentrated using macroporous resin and acid precipitation showed no antifungal activity against , whereas the crude protein obtained by ammonium sulfate precipitation disrupted not only the cell wall and cell membrane of hyphae, induced intracellular reactive oxygen species (ROS) burst but also lysed spores and inhibited spore germ tube elongation. Enzyme substrate profile assays indicated that several peptidases, lipases, and glycoside hydrolases secreted by HM-E might play important roles in its antifungal process and are potential biocontrol factors. This study suggests HM-E, as a novel biocontrol agent, has great potential for application in the combating of cotton Verticillium wilt.
由[病原菌名称缺失]引起的棉花黄萎病是棉花生产中最具毁灭性的土传真菌病害之一，迫切需要开发有效的防治措施。粘细菌是一类表现出多细胞社会行为的高等原核生物，对植物病原真菌和细菌具有捕食活性，使其在植物病害生物防治中具有独特的应用潜力。在本研究中，基于先前收集的粘细菌菌株，筛选出一株具有广谱抗真菌活性的粘细菌菌株HM-E。通过形态观察、生理生化特性分析和多位点序列分析，该菌株被鉴定为[具体菌种名称缺失] HM-E。HM-E不仅能显著裂解[病原菌名称缺失]的菌丝，还能抑制其孢子萌发。其无细胞发酵滤液和挥发性代谢产物均表现出一定的抗真菌活性。温室盆栽试验表明，HM-E的发酵液对棉花黄萎病的防治效果仅为23.01%，而用白星花金龟（[昆虫名称缺失]）粪便配制的固体剂防治效果显著提高，达到70.90%，且粘细菌固体剂还显著促进了棉苗生长。此外，大孔树脂浓缩和酸沉淀得到的粗提物对[病原菌名称缺失]没有抗真菌活性，而硫酸铵沉淀得到的粗蛋白不仅破坏了[病原菌名称缺失]菌丝的细胞壁和细胞膜，诱导细胞内活性氧（ROS）爆发，还能裂解孢子并抑制孢子萌发管伸长。酶底物谱分析表明，HM-E分泌的几种肽酶、脂肪酶和糖苷水解酶可能在其抗真菌过程中发挥重要作用，是潜在的生物防治因子。本研究表明，HM-E作为一种新型生物防治剂，在防治棉花黄萎病方面具有巨大的应用潜力。
