P-035 - Light intensity modulates the biocontrol efficacy of Bacillus amyloliquefaciens PMB05 to bacterial soft rot disease

Bacterial soft rot is a serious disease that occur on vegetable plants. Our previous studies show that this disease can be controlled by using plant immunity intensifying Bacillus amyloliquefaciens PMB05. Photosynthesis play a key factor during the activation of plant immunity intensification. The efficiency of photosynthesis is positively correlated to light intensity. However, whether the regulation of light intensity can affect the function of B. amyloliquefaciens PMB05 on the strength of plant immune response and disease resistance need to be further investigated. In this study, our result demonstrated that increasing the light intensity increased the HrpN-mediated ROS generation rather than callose deposition in Arabidopsis thaliana. Moreover, these effects were further enhanced by B. amyloliquefaciens PMB05. More importantly, the occurrence of bacterial soft rot was significantly reduced following the increase of light intensity, and B. amyloliquefaciens PMB05 also exhibited best biocontrol efficacy under higher light intensities. We further found that the decrease in bacterial soft rot severity was associated with the closing rate of stomata during PAMP-triggered immunity. We concluded that the combination of increasing light intensity and B. amyloliquefaciens PMB05 treatment would be a significant way to control bacterial soft rot.

Keywords: Light intensity, biological control