Unraveling the Molecular Basis of Bacillus Megaterium Interactions in Rice for Plant Growth Promotion Through Proteomics and Gene Expression

Abstract

In this study, we evaluated the efcacy of Bacillus strains for plant growth promotional activities under in vitro and in vivo conditions. The results indicated that Bacillus megaterium BS11 was superior in enhancing the plant growth and yield of rice plants compared to other Bacillus strains. Currently, there is no information available on the molecular mechanism of Rice–B. megaterium interaction for plant growth promotion. Thus, the present study was undertaken to understand the molecular basis of Rice–B. megaterium interaction at the proteome level using the two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) approach. Proteomic results revealed that a total of 17 proteins were diferentially expressed in response to BS11 inoculation. The application of BS11 up-regulated most of the identifed proteins involved in plant metabolism, transcription, transporter, signaling, defense, and stress responses, which may underlie the improvement of rice plant growth. Furthermore, the proteomic results were validated at the mRNA level by Quantitative Real-Time PCR (qPCR) analysis. The abundances of proteins and transcripts were positively correlated for all genes except LOC_Os01g68620. Overall, our results suggest that B. megaterium strain BS11 may promote plant growth by improving various metabolism in rice plants.