Differential Expression of In Vivo and In Vitro Protein Profile of Outer Membrane of Acidovorax avenae Subsp. avenae

Abstract

Outer membrane (OM) proteins play a significant role in bacterial pathogenesis. In this work, we examined and compared the expression of the OM proteins of the rice pathogen Acidovorax avenae subsp. avenae strain RS-1, a Gram-negative bacterium, both in an in vitro culture medium and in vivo rice plants. Global proteomic profiling of A. avenae subsp. avenae strain RS-1 comparing in vivo and in vitro conditions revealed the differential expression of proteins affecting the survival and pathogenicity of the rice pathogen in host plants. The shotgun proteomics analysis of OM proteins resulted in the identification of 97 proteins in vitro and 62 proteins in vivo by mass spectrometry. Among these OM proteins, there is a high number of porins, TonB-dependent receptors, lipoproteins of the NodT family, ABC transporters, flagellins, and proteins of unknown function expressed under both conditions. However, the major proteins such as phospholipase and OmpA domain containing proteins were expressed in vitro, while the proteins such as the surface anchored protein F, ATP-dependent Clp protease, OmpA and MotB domain containing proteins were expressed in vivo. This may indicate that these in vivo OM proteins have roles in the pathogenicity of A. avenae subsp. avenae strain RS-1. In addition, the LC-MS/MS identification of OmpA and MotB validated the in silico prediction of the existance of Type VI secretion system core components. To the best of our knowledge, this is the first study to reveal the in vitro and in vivo protein profiles, in combination with LC-MS/MS mass spectra, in silico OM proteome and in silico genome wide analysis, of pathogenicity or plant host required proteins of a plant pathogenic bacterium.

Transcriptome analysis of Acidovorax avenae subsp. avenae cultivated in vivo and co-culture with Burkholderia seminalis

“…Therefore, it is also necessary to examine the transcriptional response of rice pathogen Aaa to other rice associated bacteria such as Burkholderia seminalis strain R456, which was isolated from rice rhizosphere and is nonpathogenic to rice. B. seminalis strain R456 protected rice seedlings from infection by Rhizoctonia solani in our previous studies112.…”

“…The samples of Aaa strain RS-1 for in vitro and in vivo analysis were prepared as described before1. The co-culture analysis was conducted according to Di Cagno et al 30.…”

Halotolerant bacteria belonging to operational group Bacillus amyloliquefaciens in biocontrol of the rice brown stripe pathogen Acidovorax oryzae

“…; Ibrahim et al . ). In rice, this pathogen causes bacterial brown stripe disease (BBS) with massive economic losses in many rice‐growing countries (Xie et al .…”

Characterization and functional analysis of clpB gene from Acidovorax avenae subsp. avenae RS‐1

“…The Gram-negative bacterium Acidovorax avenae subsp. avenae (Aaa) is known to infect many plant species, including rice, corn, oats, sugarcane, millet and foxtail (Ibrahim et al, 2012). In rice, this widely distributed seedborne pathogen causes bacterial brown stripe, which has been reported in many countries in Asia, Africa, North America and Europe (Wang et al, 2012).…”