Proteômica comparativa de isolados de Xanthomonas campestris pv. campstris contrastantes em virulência

Abstract

The phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc) consist in the black rot disease causal agent, which affects all Brassica genus commercial varieties. This disease results in significant losses for brassicultures worldwide. The present study aimed to analyze the proteomic profile of two distinct Xcc isolates, employing an in vitro system for the identification of differentially abundant proteins, related to pathogenicity and virulence mechanisms. Initially, bacterial growth curves were assessed to determine the appropriate stage for protein extraction. Xanthomonas isolates Xcc51 and XccY21 were cultured in two distinct mediums, a nutritionally rich medium (NYG) and a minimal medium - XVM1, capable of inducing the transcription of pathogenicity genes, until they reached maximum exponential growth phase (OD600nm = 0.8 A. and OD600nm = 0.52 A., respectively). Total proteins were extracted using phenol/ammonium acetate, trypsin digested and analyzed by 2DnanoUPLC/MSE, coupled with Protein Lynx Global Server (PLGS). Xanthomonas Genome Browser database was used, leading to the identification of more than 600 proteins and revealing the expression of unique proteins as well as diverse profiles of increased and decreased proteins. Blast2GO software was applied to analyze gene ontology. Results suggest that during pathogenicity inducing condition, the isolate Xcc51 increases the abundance of crucial infection-related proteins such as bfeA, TonB, ompP6, clpB, acvB, when compared to XccY21 which could explain its higher virulence. The proteomic data showed by the present study delivered a list of interesting proteins presumably related with pathogenicity and virulence of Xcc, which could guide future investigations on molecular mechanisms involved in this phytobacterium pathogenesis.