Strain PMB05 Intensifies Plant Immune Responses to Confer Resistance Against Bacterial Wilt of Tomato.

Tomato is an economic crop worldwide. Many limiting factors reduce the production of tomato, with bacterial wilt caused by being the most destructive disease. Our previous study showed that the disease resistance to bacterial soft rot is enhanced by strain PMB05. This enhanced resistance is associated with the intensification of pathogen-associated molecular patterns (PAMP)-triggered immunity (PTI). To determine whether the PTI-intensifying spp. strains are able to confer disease resistance to bacterial wilt, their effects on PTI signals triggered by PAMP from and on the occurrence of bacterial wilt were assayed. Before assay, a gene that encodes harpin from , PopW, was applied as a PAMP. Results revealed that the strain PMB05 was the one strain among 9 rhizobacterial strains which could significantly intensify the PopW-induced hypersensitive response (HR) on leaves. Moreover, we observed that the signals of PopW-induced reactive oxygen species generation and callose deposition were increased, confirming that the PTI was intensified by PMB05. The intensification of the PopW-triggered HR by PMB05 in was reduced upon treatment with inhibitors in PTI pathways. Furthermore, the application of spp. strains on tomato plants showed that only the use of PMB05 resulted in significantly increased resistance to bacterial wilt. Moreover, the PTI signals were also intensified in the tomato leaves. Taken together, we demonstrated that PMB05 is a PTI-intensifying bacterium that confers resistance to tomato bacterial wilt. Screening of plant immunity intensifying rhizobacteria is a possible strategy to control tomato bacterial wilt.[Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.