Expression analysis of Arabidopsis mpk11 mutant treated with flg22

Arabidopsis MPK11 is activated and plays a role in the flg22 sensing. Mitogen-activated protein kinases (MAPKs) mediate cellular signal transduction during stress responses, as well as diverse growth and developmental steps in eukaryotes. Pathogen infection or treatment with conserved pathogen-associated molecular patterns (PAMPs) such as the bacterial flagellin-derived flg22 peptide are known to activate three Arabidopsis thaliana MAPKs, MPK3, MPK4 and MPK6. Several stresses, including flg22 treatment, are known to increase MPK11 expression but activation of MPK11 has not been shown. Here, we show that MPK11 activity can indeed be increased through flg22 elicitation. Expression profiling using a small-scale microarray for defense-related genes revealed that cinnamyl alcohol dehyrogenase 5 (CAD5) requires MPK11 for full flg22-induced expression. An mpk11 mutant showed increased flg22-mediated growth inhibition but no altered susceptibility to Pseudomonas syringae, Botrytis cinerea or Alternaria brassicicola. A 24 DNA microarray study using toral RNA from an Arabidopsis mutant (mpk11 SALK049352) as well as wild type treated with water or flg22.