Volatile organic compounds produced by Pseudomonas fluorescens WR-1 restrict the growth and virulence traits of Ralstonia solanacearum.

The volatile organic compounds (VOCs) produced by soil microbes have a significant role in the control of plant diseases and plant growth promotion. In this study, we examined the effect of VOCs produced by Pseudomonas fluorescens strain WR-1 on the growth and virulence traits of tomato wilt pathogen Ralstonia solanacearum. The VOCs produced by P. fluorescens WR-1 exhibited concentration dependent bacteriostatic effect on the growth of R. solanacearum on agar medium and in infested soil. The VOCs of P. fluorescens WR-1 also significantly inhibited the virulence traits of R. solanacearum. The proteomics analysis showed that the VOCs of P. fluorescens WR-1 downregulated cellular proteins of R. solanacearum related to the antioxidant activity, virulence, inclusion body proteins, carbohydrate and amino acid synthesis and metabolism, protein folding and translation, methylation and energy transfer, while the proteins involved in the ABC transporter system, detoxification of aldehydes and ketones, protein folding and translation were upregulated. This study revealed the significance of VOCs of P. fluorescens WR-1 to control the tomato wilt pathogen R. solanacearum. Investigation of the modes of action of biocontrol agents is important to better comprehend the interactions mediated by VOCs in nature to design better control strategies for plant pathogens.