P-036 - Screening plant immunity intensifying microbial strains to enhance disease resistance to bacterial soft rot in Chinese cabbage

Bacterial soft rot of Chinese cabbage is a devastating disease caused by Pectobacterium carotovorum subsp. carotovorum, which leads to significant economic losses. Instead of chemical control, biological control by beneficial microorganisms would be feasible and a healthier option. Our previous studies demonstrate a plant immunity intensifying microbe that can effectively control various plant diseases. In addition, a screening system to select bacterial strain with this function by AtGSL5-GFP transgenic plant was established. In this study, we use AtGSL5-GFP system to obtain Bacillus spp. RIAT136 and Pseudomonas laurentiana RIAT177. These two strains were able to intensify ROS generation and callose deposition upon PAMP treatment. Moreover, these two strains also reduced soft rot disease in Arabidopsis. We further demonstrated that the plant immune responses and disease control in Chinese cabbage were improved by these two strains. To enhance the disease control by using adhesin. Our result showed 0.1% xanthan gum may accelerate the effects of these two strains on stomata closure. However, this effect did not further enhance disease control efficacy. We concluded that using two novel plant immunity intensifying strains, RIAT136 and RIAT177 to control bacterial soft rot in Chinese cabbage would be promising.

Keyword: Biocontrol, Plant health, Adhesin, Induce resistance