Phylogenetic Characterization lcrD Gene Family: Molecular Evolutionary Aspects of Pathogen‐Induced Hypersensitivity in plants

— Hrp (hypersensitivity response and pathogenicity) genes encode signal‐peptide independent transporter molecules that function in the Type III secretion pathway and are present in a number of plant pathogenic bacterial species. These Hrp transporter molecules largely export harpin and other virulence factors across the bacterial membrane and onto the Hrp loci are part of a larger lcr D family which encode the low calcium response proteins. Members of this family serve to transport a number of diverse virulence factors in a variety of enteric and other purple bacteria species both pathogenic hrp ‐induced pathogenicity by different plant pathogenic bacterial species is the result of a single evolutionary event or evolved independently, cladistic analyses were performed lcr D gene family. The results of these studies lcr D or hrp genes lcr D homologues which comprised the other two hrp transporter genes do not capture the phylogenetic history of their host bacterial lcr D gene was horizontally introduced into each of four different plant pathogenic species which may have resulted from four independent transfer events. This monophyletic partitioning of hrp genes precludes their use as reliable taxonomic markers while further supporting the current notion that hrp transport