title: Distinct carbohydrate and lipid-based molecular patterns within lipopolysaccharides from Burkholderia cepacia contribute to defense-associated differential gene expression in Arabidopsis thaliana.
abstract: Lipopolysaccharides are structural components within the cell walls of Gram-negative bacteria. The LPSs as microbe-associated molecular pattern (MAMP) molecules can trigger defense-related responses involved in MAMP-triggered immunity and basal resistance in plants, presumably from an initial perception event. LPS from Burkholderia cepacia as well as two fragments, the glycolipid, lipid A and the polysaccharide (OPS-core) chain, were used to treat Arabidopsis thaliana seedlings to evaluate the eliciting activities of the individual LPS sub-domains by means of Annealing Control Primer-based Differential Display transcript profiling. Genes found to be up-regulated encode for proteins involved in signal perception and transduction, transcriptional regulation and defense - and stress responses. Furthermore, genes encoding proteins involved in chaperoning, secretion, protein-protein interactions and protein degradation were differentially expressed. It is concluded that intact LPS, as well as the two sub-components, induced the expression of a broad range of genes associated with perception and defense as well as metabolic reprogramming of cellular activities in support of immunity and basal resistance. Whilst the lipid A and OPS moieties were able to up-regulate sub-sets of defense-associated genes over the same spectrum of categories as intact LPS, the up-regulation observed with intact LPS was the more comprehensive, suggesting that the lipid A and glycan molecular patterns of the molecule act as partial agonists, but that the intact LPS structure is required for full agonist activity.
authors: Department of Biochemistry, University of Johannesburg, Johannesburg, South Africa.
authors: Ntakadzeni E
authors: NE
authors: Madala
authors: Antonio
authors: A
authors: Molinaro
authors: Ian A
authors: IA
authors: Dubery
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D016956:Burkholderia cepacia / Q000276:immunology*; D018744:DNA, Plant / Q000032:analysis; D020869:Gene Expression Profiling; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D008050:Lipid A / Q000737:chemistry; D008070:Lipopolysaccharides / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D015394:Molecular Structure; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology*; D036226:Seedlings / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D013329:Structure-Activity Relationship
chemical_list: D018744:DNA, Plant; D008050:Lipid A; D008070:Lipopolysaccharides