Pan Proteome of Xanthomonas campestris pv. campestris Isolates Contrasting in Virulence

Abstract

Fully sequenced genomes of Xanthomonas campestris pv. campestris (Xcc) strains are reported. However, intra‐pathovar differences are still intriguing and far from clear. In this work, the contrasting virulence between two isolates of Xcc ‐ Xcc51 (more virulent) and XccY21 (less virulent) is evaluated by determining their pan proteome profiles. The bacteria are grown in NYG and XVM1 (optimal for induction of hrp regulon) broths and collected at the max‐exponential growth phase. Shotgun proteomics reveals a total of 329 proteins when Xcc isolates are grown in XVM1. A comparison of both profiles reveals 47 proteins with significant abundance fluctuations, out of which, 39 show an increased abundance in Xcc51 and are mainly involved in virulence/adaptation mechanisms, genetic information processing, and membrane receptor/iron transport systems, such as BfeA, BtuB, Cap, Clp, Dcp, FyuA, GroEs, HpaG, Tig, and OmpP6. Several differential proteins are further analyzed by qRT‐PCR, which reveals a similar expression pattern to the protein abundance. The data shed light on the complex Xcc pathogenicity mechanisms and point out a set of proteins related to the higher virulence of Xcc51. This information is essential for the development of more efficient strategies aiming at the control of black rot disease.

A Comprehensive Overview of the Genes and Functions Required for Lettuce Infection by the Hemibiotrophic Phytopathogen Xanthomonas hortorum pv. vitians

“…Iron uptake using siderophores is indeed a well-known crucial feature of most bacterial phytopathogens necessary for successful host invasion ( 63 ). A recent proteomic analysis suggested that BfeA protein abundance could be directly correlated with virulence ( 64 ), which could partially explain why the gene is present in the form of three colocalized copies. However, further studies would have to elucidate why only one copy of bfeA is critical for fitness in planta .…”