title: Effects of volatile organic compounds produced by Bacillus amyloliquefaciens on the growth and virulence traits of tomato bacterial wilt pathogen Ralstonia solanacearum.
abstract: The production of volatile organic compounds (VOCs) by microbes is an important characteristic for their selection as biocontrol agents against plant pathogens. In this study, we identified the VOCs produced by the biocontrol strain Bacillus amyloliquefaciens T-5 and evaluated their impact on the growth and virulence traits of tomato bacterial wilt pathogen Ralstonia solanacearum. The results showed that the VOCs of strain T-5 significantly inhibited the growth of R. solanacearum in agar medium and in soil. In addition, VOCs significantly inhibited the motility traits, root colonization, biofilm formation, and production of antioxidant enzymes and exopolysaccharides by R. solanacearum. However, no effect of VOCs on the production of hydrolytic enzymes by R. solanacearum was observed. The strain T-5 produced VOCs, including benzenes, ketones, aldehydes, alkanes, acids, and one furan and naphthalene compound; among those, 13 VOCs showed 1-10 % antibacterial activity against R. solanacearum in their produced amounts by T-5; however, the consortium of all VOCs produced on agar medium, in sterilized soil, and in natural soil showed 75, 62, and 85 % growth inhibition of R. solanacearum, respectively. The real-time PCR analysis further confirmed the results when the expression of different virulence- and metabolism-related genes in R. solanacearum cells was decreased after exposure to the VOCs of strain T-5. The results of this study clearly revealed the significance of VOCs in the control of plant pathogens. This information would help to better comprehend the microbial interactions mediated by VOCs in nature and to develop safer strategies to control plant disease.
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Wei Gang Road, No. 1, 210095, Nanjing, Jiangsu Province, People's Republic of China.
authors.forename: Waseem
authors.initials: W
authors.lastname: Raza
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Wei Gang Road, No. 1, 210095, Nanjing, Jiangsu Province, People's Republic of China.
authors.forename: Jichen
authors.initials: J
authors.lastname: Wang
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Wei Gang Road, No. 1, 210095, Nanjing, Jiangsu Province, People's Republic of China.
authors.forename: Yuncheng
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Wei Gang Road, No. 1, 210095, Nanjing, Jiangsu Province, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Ling
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Wei Gang Road, No. 1, 210095, Nanjing, Jiangsu Province, People's Republic of China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Wei Gang Road, No. 1, 210095, Nanjing, Jiangsu Province, People's Republic of China.
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Wei Gang Road, No. 1, 210095, Nanjing, Jiangsu Province, People's Republic of China. shenqirong@njau.edu.cn.
authors.forename: Qirong
authors.initials: Q
authors.lastname: Shen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000069977:Bacillus amyloliquefaciens / Q000378:metabolism*; D061046:Biological Control Agents / Q000378:metabolism / Q000494:pharmacology*; D018551:Solanum lycopersicum / Q000382:microbiology; D010935:Plant Diseases / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D043368:Ralstonia solanacearum / Q000254:growth & development* / Q000472:pathogenicity*; D055549:Volatile Organic Compounds / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D061046:Biological Control Agents; D055549:Volatile Organic Compounds
keywords: Antibacterial; Ralstonia solanacearum; Virulence traits; Volatile compounds