Chitin elicitation timecourse

Chitin oligomers, released from fungal cell walls by endochitinase, induce defense and related cellular responses in many plants. However, little is known about chitin responses in the model plant Arabidopsis. We describe here a large scale characterization of gene expression patterns in Arabidopsis in response to chitin treatment using an Arabidopsis microarray consisting of 2,375 EST clones representing putative defense-related and regulatory genes. Transcript levels for 71 ESTs, representing 61 genes, were altered >3-fold in chitin-treated seedlings relative to control seedlings. A number of transcripts exhibited altered accumulation as early as 10 min after exposure to chitin, representing some of the earliest changes in gene expression observed in chitin-treated plants. Included among the 61 genes are those that have been reported to be elicited by various pathogen-related stimuli in other plants. Additional genes, including genes of unknown function, were also identified broadening our understanding of chitin-elicited responses. Among transcripts with enhanced accumulation, one cluster was enriched in genes with both the W-box promoter element and a novel regulatory element. In addition, a number of transcripts had decreased abundance, encoding several proteins involved in cell wall strengthening and wall deposition. The chalcone synthase promoter element was identified in the upstream regions of these genes, suggesting that pathogen signals may suppress expression of some genes. These data indicate that Arabidopsis will be an excellent model to elucidate mechanisms of chitin elicitation in plant defense. Groups of assays that are related as part of a time series. Keywords: time_series_design Computed