Pathogenicity Analysis Of ClpB, ImpM Gene Of Acidovorax Orvzae And Their Protein Expression Under Oxidative Stress

The Gram-negative bacterium Acidovorax oryzae is the causal agent of bacterial brown stripe (BBS), which can cause severe diseases in many crops, including rice. Gene ClpB of A.oryzae in Type VI secretion system (T6SS) is involved in hydrolyzing ATP to provide energy for effector proteion and Gene ImpM in T6SS controls several bacterial activities such as bacterial surface motility, surface adherence, and colonization. However, whether gene ClpB and ImpM are related to pathogenisis is unknown. The present study is to characterize the association of A.oryzae ClpB and ImpM with pathogenicity in rice. We generated homologous recombination mutatnts. The insertional mutagenesises on the background of this bacterium were identified as reduced pathogenicity. The ClpB-deficient mutant strain and ImpM-deficient mutant strain seriously affected the extraction extracellular polymers, including production, characteristic and virulence. Collectively, our data clearly indicated that the ClpB and ImpM gene of A.oryzae play a key role in rice pathogenicity, which may control the EPS effector.Differential expressions of proteins of A.oryzae RS-1strain under in vitro, and in vitro with pesticide paraquat induced oxidative stress were conducted because bacteria survival in unstable environment requires a wide range of rapid adaptive responses triggered or mediated by regulatory proteins. The results showed that some proteins like ABC transporter, Chaperone protein DnaK,30S ribosomal protein, Superoxide dismutase, OmpA/MotB only presented under in oxidative stress. In particular, OmpA/MotB was T6SS core components, demonstrating that T6SS may be involved in the survival and pathogenicity of A. oryzae strain RS-1in host plants.