PGPR induces resistance against soft rot on Chinese green mustard

Abstract: Plant growth promotion rhizobacterium (PGPR), Bacillus subtilis strain CaSUT007 was isolated from soil in northeast of Thailand. Application of CaSUT007 reduced the disease severity of soft rot up to 60% when compared to pathogen inoculated control plants. Our results revealed that phenolic compounds were found to accumulate in Chinese green mustard leaf tissues treated with CaSUT007 when plants were 5 days old, with the level of phenolic compounds reaching 2.05 μg/g fresh weight. FT-IR analyses indicated that protein was highly accumulated in response to the strain CaSUT007. Chinese green mustard treated with CaSUT007 showed changes in the beta sheet secondary structure of proteins and appeared to have a higher polysaccharide content, but lipid content was decreased compared with plants treated with distilled water. These results demonstrate that the application of PGPR strain CaSUT007 has potential to control soft rot disease and reduce the risk associated with high use of chemical pesticides in commercial Chinese green mustard production in Thailand.