Transcript profile of transgenic Arabidopsis constitutively producing methyl jasmonate

Using an Affymetrix GeneChip((R)) containing 8300 oligonucleotide probes, we measured transcript levels in transgenic Arabidopsis overexpressing the jasmonate carboxyl methyltransferase gene (AtJMT). When compared with wild-type plants, 5week-old transgenics exhibited significant alterations (more than a two-fold increase or decrease) in the expression levels of 168 genes. Among them, 80 were up-regulated, including those involved in defense, oxidative stress-tolerance, and senescence. In contrast, the expression of 88 genes, including those that function in photosynthesis and cold/drought-stress responses, was significantly down-regulated. Thus, endogenous generation of methyl jasmonate through AtJMT-overexpression modified the transcript levels of genes previously identified as being jasmonate-responsive. This result confirms that MeJA formation is a key control point for jasmonate-responsive gene expression in plants.