Multi-omics analysis reveals the specific role of biocontrol reagents against tomato bacterial wilt

Jiang Lu^1*Xin-Qiao Du¹Tian-Xiao Sun¹Wu-Lin Xu²Tang Zhu³Qiang Wang⁴Peiwen Gu^5*

• ¹School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
• ²Chengdu Topu Biotechnology Co., LTD, Chengdu, China
• ³Chengdu Juzhuo Biotechnology Co., LTD, Chengdu, China
• ⁴Sichuan Taikang Biotechnology Co., LTD, Chengdu, China
• ⁵School of Agriculture Ningxia University, Yinchuan, China

Bacterial wilt caused by Ralstonia solanacearum is considered one of the most important diseases that cause economic losses to tomato. Currently, eco-friendly biocontrol agents have been increasingly considered as effective approaches to control tomato bacterial wilt. However, the specific mechanisms by which biocontrol bacteria with distinct functions exert their effects remain unclear. In this study, we showed that the fermentation broth of Bacillus velezensis or Pseudomonas fluorescens inhibited the growth of R. solanacearum in vitro, and improves the ability of tomato plants against bacterial wilt. We employed a combination of amplicon sequencing, transcriptomics, and metabolomics analysis to investigate how these biocontrol agents affect the defense responses against R. solanacearum in tomato. In general, different biocontrol agents protect plants from bacterial wilt in many ways, by recruiting specific microbial communities in rhizosphere soil and activating different synthetic/metabolic and signaling pathways. Collectively, our findings contribute to a more in-depth understanding in disease resistance mechanisms of biocontrol agents, and provide a theoretical foundation for the development of targeted strategies using beneficial microorganisms to suppress disease occurrence.