MOLECULAR BASIS OF INTERACTIONS BETWEEN PLANT AND PLANT GROWTH PROMOTING RHIZOBACTERIA

Abstract

Engineering the rhizosphere with plant growth promoting rhizobacteria (PGPR) is a promising strategy to increase agricultural output to feed the growing world population. In this study, three known Pseudomonas spp PGPR strains were screened for plant growth promoting capabilities at a distance from the plant root, using the Arabidopsis model. The best performing PGPR strain was found to promote plant growth through bioactive volatile(s). Interestingly, RNA sequencing of the PGPR of interest exposed to plant root exudates and/or plant volatiles in a time-series assay revealed plant root exudates and plant volatiles affected the bacterial transcriptome at different time-points. Plant volatiles induced gene expression profiles indicative of biofilm formation by the PGPR Pseudomonas sp., while plant root exudates induced antimicrobial resistance. This discovery of the role of plant volatiles in inducing PGPR into a biofilm way of life opens a new paradigm in plant-bacteria interactions.