RECEPTOR-MEDIATED ACTIVATION OF A MAP KINASE IN PATHOGEN DEFENSE OF PLANTS

Parsley cells recognize the fungal plant pathogen Phytophthora sojae t hrough a plasma membrane receptor. A pathogen-derived oligopeptide eli citor binds to this receptor and thereby stimulates a multicomponent d efense response through sequential activation of ion channels and an o xidative burst. An elicitor-responsive mitogen-activated protein (MAP) kinase was identified that acts downstream of the ion channels but in dependently or upstream of the oxidative burst. Upon receptor-mediated activation, the MAP kinase is translocated to the nucleus where it mi ght interact with transcription factors that induce expression of defe nse genes.