MAP-kinase activity in etiolated Cucumis sativus cotyledons: The effect of red and far-red light irradiation

► Two PKs with MAPK properties were detected in etiolated cucumber cotyledons. ► FR light rapidly and transiently stimulated MAPK activity by a VLFR of phytochrome. ► The results suggest that MAPKs are involved in phytochrome signal transduction.