Dong Xiaomin, Liu Xiaoran, Hu Lifang, Zhang Shiyu, Jia Ruimin, Cao Shang, Wang Yang
College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
Pestic Biochem Physiol. 2025 Nov;214:106574. doi: 10.1016/j.pestbp.2025.106574. Epub 2025 Jul 12.
Tomato Fusarium wilt, caused by the soil-borne pathogen Fusarium oxysporum f. sp. lycopersici (Fol), poses a significant threat to global tomato production, resulting in severe losses in both yield and quality. In this study, an actinomycete was isolated from soil and identified as a novel strain, Streptomyces haidianensis sp. nov. LX-29, based on polyphasic analyses and taxonomical characterization. In vitro antagonism assays demonstrated that LX-29 showed broad-spectrum antifungal activity and strong antifungal activity against Fol, with an inhibition zone width of 13.75 ± 0.29 mm. Genomic analysis revealed that LX-29 encodes 39 secondary metabolites biosynthetic gene clusters, indicating its potential for producing a diverse array of antifungal secondary metabolites. In pot experiments, LX-29 significantly enhanced the activities of defense-related enzymes in tomatoes, reduced disease incidence, and promoted plant growth. Moreover, the colonization assay revealed that LX-29 colonized tomato roots. Further experiments indicated that the ethyl acetate extracts of fermentation broth from LX-29 inhibited Fol spore germination, disrupted the cell membrane of the pathogen, and caused morphological changes in the hyphae and spores. GC-MS analysis identified a range of antimicrobial substances in the crude extracts, showing the diverse antifungal mechanisms of LX-29. Overall, these findings demonstrate the substantial biocontrol potential of LX-29 against tomato Fusarium wilt, marking it as a promising candidate for sustainable agricultural practices.
番茄枯萎病由土壤传播的病原菌尖孢镰刀菌番茄专化型（Fol）引起，对全球番茄生产构成重大威胁，导致产量和品质严重损失。在本研究中，从土壤中分离出一种放线菌，经多相分析和分类学鉴定，确定为一个新菌株，海淀链霉菌新种LX-29。体外拮抗试验表明，LX-29具有广谱抗真菌活性，对Fol具有较强的抗真菌活性，抑菌圈宽度为13.75±0.29毫米。基因组分析表明，LX-29编码39个次生代谢物生物合成基因簇，表明其具有产生多种抗真菌次生代谢物的潜力。盆栽试验中，LX-29显著提高了番茄中防御相关酶的活性，降低了发病率，并促进了植株生长。此外，定殖试验表明LX-29定殖于番茄根部。进一步实验表明，LX-29发酵液的乙酸乙酯提取物抑制Fol孢子萌发，破坏病原菌细胞膜，并导致菌丝和孢子形态变化。气相色谱-质谱分析在粗提物中鉴定出一系列抗菌物质，表明LX-29具有多种抗真菌机制。总体而言，这些发现证明了LX-29对番茄枯萎病具有巨大的生防潜力，使其成为可持续农业实践的一个有前景的候选菌株。
