Zhong Jie, Sui Wen Wen, Li Xiao Gang, Zhang Zhuo, Zhu Jun Zi
Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, Hunan Province 410128, PR China.
Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, Hunan Province 410125, PR China.
Pestic Biochem Physiol. 2025 Sep;213:106545. doi: 10.1016/j.pestbp.2025.106545. Epub 2025 Jul 3.
Rhizoctonia solani is a widespread and destructive plant pathogenic fungus that infects numerous important crops, including tobacco, where it causes tobacco target spot, a disease that severely impacts production. In this study, a strain ZZ-48, isolated from the rhizosphere soil of forests, exhibited strong antifungal activity with a 79.39 % inhibition rate against R. solani and various other fungal pathogens. Strain ZZ-48 was identified as Kitasatospora purpureofusca based on its phenotypic, physiological and biochemical, and genetic characteristics. This strain significantly reduced the development of tobacco target spot both in vitro and in vivo. ZZ-48 treatment significantly disrupted the mycelia structure of R. solani. Furthermore, the culture filtrate disrupted plasma membrane integrity and promoted reactive oxygen species accumulation and lipid peroxidation in the mycelia of R. solani. Additionally, ZZ-48 secreted multiple extracellular enzymes and siderophores. Bioactive metabolites were inferred to be present in the crude lipopeptide extracts, which exhibited a median effect concentration (EC) value of 1.60 ± 0.18 μg/mL. Furthermore, several key biosynthetic gene clusters (BCGs) associated with the synthesis of bioactive metabolites were found in the genome of ZZ-48 using antiSMASH. Overall, strain ZZ-48 holds significant potential as a biocontrol agent for managing tobacco target spot.
立枯丝核菌是一种广泛存在且具有破坏性的植物病原真菌，可感染包括烟草在内的多种重要作物，在烟草上引发烟草靶斑病，该病严重影响产量。在本研究中，从森林根际土壤中分离出的菌株ZZ - 48对立枯丝核菌和其他多种真菌病原体表现出强大的抗真菌活性，抑制率达79.39%。基于其表型、生理生化及遗传特征，菌株ZZ - 48被鉴定为紫褐北里孢菌。该菌株在体外和体内均显著降低了烟草靶斑病的发展。ZZ - 48处理显著破坏了立枯丝核菌的菌丝体结构。此外，培养滤液破坏了细胞膜完整性，促进了立枯丝核菌菌丝体中活性氧的积累和脂质过氧化。此外，ZZ - 48分泌多种胞外酶和铁载体。推测粗脂肽提取物中存在生物活性代谢产物，其半数效应浓度（EC）值为1.60±0.18μg/mL。此外，使用antiSMASH在ZZ - 48的基因组中发现了几个与生物活性代谢产物合成相关的关键生物合成基因簇（BCG）。总体而言，菌株ZZ - 48作为防治烟草靶斑病的生物防治剂具有巨大潜力。
