Analysis of defense gene expression in mkk6 and CA-MPK4 mkk6-2. A, GO enrichment analysis of the biological functions of genes differentially expressed in mkk6-2 compared to wild type. The top 10 significantly enriched GO terms (determined through the PANTHER statistical overrepresentation test, P < 0.05) ranked by enrichment scores are shown. Blue bars represent significantly enriched GO terms for upregulated genes, and red bars represent significantly enriched GO terms for downregulated genes. B and C, PR1 (B) and PR2 (C) expression levels in wild type (WT) and mkk6-2. Error bars represent standard deviations from three measurements. D, Morphology of 3-week-old wild-type, mkk6-2, and CA-MPK4 mkk6-2 plants. E and F, PR1 (E) and PR2 (F) expression levels in wild-type, mkk6-2, and CA-MPK4 mkk6-2. Error bars represent standard deviations from three measurements.