Comprehensive analysis of early response genes to two different microbial elicitors in tobacco cells

The key to understanding the molecular mechanism of the defense response triggered by recognition of pathogen- or microbe-associated molecular patterns (PAMPs or MAMPs) is the identification and comparison of a set of early response genes to different microbial elicitors. We performed comprehensive and detailed monitoring of gene expression over time after application of two different microbial elicitors, PiE (an elicitor from the cell walls of an oomycete, Phytophthora infestans) and TvX (a xylanase from a fungus, Trichoderma viride), in tobacco cultured cells using the suppression subtractive hybridization and cDNA macroarray techniques. We identified various kinds of genes that are up- or down-regulated at the early stages of response to the elicitors. The majority of up-regulated genes are predicted to have a role in the defense response as signaling components and transcription factors as well as the metabolism involved in the production of secondary signaling molecules and anti-microbial compounds. The overall results revealed that there is no substantial difference in the expression profiles between cells treated with two different microbial elicitors, at least during the early phase of the defense response.