The transcriptome of Arabidopsis thaliana during systemic acquired resistance

nature genetics • volume 26 • december 2000

Klaus Maleck, Aaron Levine, Thomas Eulgem, Allen Morgan, Jürg Schmid, Kay A. Lawton, Jeffery L. Dangl& Robert A. Dietrich

Summary Infected plants undergo transcriptional reprogramming during initiation of both local defence and systemic acquired resistance (SAR). We monitored gene-expression changes in Arabidopsis thaliana under 14 different SAR-inducing or SAR-repressing conditions using a DNA microarray representing approximately 25–30% of all A. thaliana genes. We derived groups of genes with common regulation patterns, or regulons. The regulon containing PR-1, a reliable marker gene for SAR in A. thaliana, contains known PR genes and novel genes likely to function during SAR and disease resistance. We identified a common promoter element in genes of this regulon that binds members of a plant-specific transcription factor family. Our results extend expression profiling to definition of regulatory networks and gene discovery in plants.