A plant-inducible gene of Xanthomonas campestris pv. campestris encodes an exocellular component required for growth in the host and hypersensitivity on nonhosts.

摘要: Using Tn4431, a transposon that allows transcriptional fusions to promoterless luciferase (lux) operon, we have isolated nonpathogenic mutant of Xanthomonas campestris pv. campestris, i.e., JS111, does not incite any the black rot symptoms on all tested cruciferous host plants (J. J. Shaw, L. G. Settles, and C. I. Kado, Mol. Plant Microbe Interact. 1:39-45, 1988). In study reported here, determined in contrast wild-type strain, JS111 is unable induce hypersensitive necrotic response nonhost such as datura, tomato, cucumber, suggesting nonpathogenic, nonhypersensitive Hrp mutant. displayed culture growth rates, exopolysaccharide production, protease, pectate lysase, cellulase, amylase, phosphatase activities comparable those strain. However, leaves was markedly attenuated. Coinoculation with strain cauliflower or radish rescued deficiency normal levels. The locus mutated cloned named hrpXc, genetic complementation analyses hrpXc were conducted. regulation expression also investigated vitro planta, using lux chloramphenicol acetyltransferase reporter gene. gene found be strongly induced leaves. This first report analysis hrp from species.