The identification of cDNAs. representing up-regulated genes induced by lipopolysaccharides from Burkholderia cepacia, was achieved by differential display of mRNAs isolated from tobacco cells. In addition to Lip-regulation of superoxide dismutase, involved in the production of the signalling and defense molecule, hydrogen peroxide; differentially expressed cDNAs, indicative of the operation of an innate immune recognition system and expression of basal resistance, were identified. These include homologs to a receptor-like protein kinase: a binding protein for the type III secreted effector protein, harpin; a virus resistance N gene; all endogenous pararetro-virus and the Pto kinase. The altered gene expression may be responsible for activation of surveillance mechanisms and enhancement or the non-self recognition capacity. The putative roles of these transcripts in I-PS-induced responses are discussed in relation to emerging concepts of innate immunity. (c) 2006 Elsevier Inc. All rights reserved.