@entity3437 . tomato (Pst) @entity70426 infects the model plants @entity958 and @entity523 , causing disease symptoms characterized by @entity39 surrounded by @entity24194 . One mechanism used by Pst @entity14348 to infect host plants is the type III protein secretion system, which is thought to deliver multiple effector proteins to the plant cell. The exact number of type III effectors in Pst @entity14348 or any other plant pathogenic bacterium is not known. All known type III effector genes of @entity3437 are regulated by @entity70427 , an NtrC family protein, and the @entity70428 alternative sigma factor, which presumably binds to a conserved cis element (called the "hrp box") in the promoters of type III secretion-associated genes. In this study, we designed a search motif based on the promoter sequences conserved in 12 published hrp operons and putative effector genes in Pst @entity14348 . Seventy-three predicted genes were retrieved from the January 2001 release of the Pst @entity14348 genome sequence, which had 95% genome coverage. The expression of the 73 genes was analysed by microarray and Northern blotting, revealing 24 genes/operons (including eight novel genes), the expression of which was consistently higher in hrp-inducing minimal medium than in nutrient-rich Luria-Bertani broth. Expression of all eight genes was dependent on the @entity70427 gene. Most were also dependent on the @entity70428 gene, but at least one was dependent on the @entity70427 gene, but not on the @entity70428 gene. An AvrRpt2-based type III translocation assay provides evidence that some of the @entity70427 -regulated novel genes encode putative effector proteins.

Identification of novel hrp-regulated genes through functional genomic analysis of the XXXX genome.

@entity70426 :: ('251701', 'Species') :: ['strain DC3000'] @entity24194 :: ('MESH:D000747', 'Disease') :: ['chlorosis'] @entity39 :: ('MESH:D009336', 'Disease') :: ['necrotic lesions'] @entity958 :: ('3702', 'Species') :: ['Arabidopsis thaliana'] @entity70428 :: ('1183040(Tax:223283)', 'Gene') :: ['hrpL', 'HrpL'] @entity14348 :: ('223283', 'Species') :: ['DC3000'] @entity523 :: ('4081', 'Species') :: ['tomato'] @entity3437 :: ('317', 'Species') :: ['Pseudomonas syringae pv', 'P. syringae'] @entity70427 :: ('1183016(Tax:223283)', 'Gene') :: ['hrpS', 'HrpS']
@entity14348 :: (223283,Species) :: ['Pseudomonas syringae pv. tomato DC3000']
