The bacterial community in the rhizosphere of Kimchi cabbage restructured by volatile compounds emitted from rhizobacterium Proteus vulgaris JBLS202

Volatiles from Proteus vulgaris JBLS202 (JBLS202) are known to promote the growth of Kimchi cabbage and Arabidopsis plants. In this study, to assess the influence of JBLS202 and its main volatile compound indole on the bacterial community in the rhizosphere, we bacterized seeds of Kimchi cabbage, and then, the changes of bacterial diversity were investigated. The abundance of total bacteria and Pseudomonas spp. in the rhizosphere significantly increased compared to that in the nonbacterized rhizosphere. The abundance of Pseudomonas spp. in the soil on one side of the I-plate, which was exposed to volatiles from JBLS202, also significantly increased. Furthermore, synthetic indole also positively stimulated the abundance and growth of Pseudomonas fluorescens and Pseudomonas putida. The average well-color development (AWCD) values and utilization patterns of carbon source was also changed by the JBLS202 volatiles. Shannon's and Simpson's diversity and evenness indexes increased in the treated rhizosphere. Overall, the results suggest that seed bacterization with JBLS202 or exposure to volatiles from JBLS202/indole modulates the soil microbial community, which influenced microbial functional and metabolic diversity. This is the foremost report on the stimulatory effects of volatile compounds from JBLS202 on the rhizosphere microbiome.