Interaction of Xanthomonas with crucifers

General studies of the bacterial pathogenXanthomonas campestris have revealed many classes of gene which are essential for pathogenicity to cruciferous plants. ‘Pathogenicity genes’ include structural genes encoding extracellular plant-degrading enzymes, genes required for the export (or secretion) of the enzymes from the bacterial cell, several independent sets of regulatory genes, a cluster ofhrp genes, and several genes of unknown function. Plants respond to infection by synthesizing characteristic pathogenesis-related proteins. The spectrum of proteins produced depends on the genotype of the challenging bacterium.Arabidopsis is susceptible to infection byXanthomonas, which should make it feasible to analyze plant resistance and response by molucular genetic techniques.