1. Characterization of the Endophytic Bacillus subtilis KRS015 Strain for Its Biocontrol Efficacy Against Verticillium dahliae .
- Author
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Song J, Wang D, Han D, Zhang DD, Li R, Kong ZQ, Dai XF, Subbarao KV, and Chen JY
- Subjects
- Bacillus subtilis genetics, Phylogeny, Plant Diseases microbiology, Gossypium genetics, Plant Extracts, Disease Resistance physiology, Gene Expression Regulation, Plant, Verticillium physiology, Ascomycota, Acremonium
- Abstract
Endophytes play important roles in promoting plant growth and controlling plant diseases. Verticillium wilt is a vascular wilt disease caused by Verticillium dahliae , a widely distributed soilborne pathogen that causes significant economic losses on cotton each year. In this study, an endophyte KRS015, isolated from the seed of the Verticillium wilt-resistant Gossypium hirsutum 'Zhongzhimian No. 2', was identified as Bacillus subtilis by morphological, phylogenetic, physiological, and biochemical analyses. The volatile organic compounds (VOCs) produced by KRS015 or its cell-free fermentation extract had significant antagonistic effects on various pathogenic fungi, including V. dahliae . KRS015 reduced Verticillium wilt index and colonization of V. dahliae in treated cotton seedlings significantly; the disease reduction rate was ∼62%. KRS015 also promoted plant growth, potentially mediated by the growth-related cotton genes GhACL5 and GhCPD-3 . The cell-free fermentation extract of KRS015 triggered a hypersensitivity response, including reactive oxygen species (ROS) and expression of resistance-related plant genes. VOCs from KRS015 also inhibited germination of conidia and the mycelial growth of V. dahliae , and were mediated by growth and development-related genes such as VdHapX , VdMcm1 , Vdpf , and Vel1 . These results suggest that KRS015 is a potential agent for controlling Verticillium wilt and promoting growth of cotton., Competing Interests: The author(s) declare no conflict of interest.
- Published
- 2024
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