title: myo-Inositol Trisphosphate Mobilizes Calcium from Fusogenic Carrot (Daucus carota L.) Protoplasts.
abstract: To determine whether or not inositol trisphosphate (IP(3)) mobilizes calcium in higher plant cells, we investigated the effect of IP(3) on Ca(2+) fluxes in fusogenic carrot (Daucus carota L.) protoplasts. The protoplasts were incubated in (45)Ca(2+)-containing medium and the (45)Ca(2+) associated with the protoplasts was monitored with time. Addition of IP(3) (20 micromolar) caused a 17% net loss of the accumulated (45)Ca(2+) within 4 minutes. There was a reuptake of (45)Ca(2+) and the protoplasts recovered to their initial value by 10 minutes. Phytic acid (IP(6)), also stimulated (45)Ca(2+) efflux from the protoplasts. Both the IP(3(-) ) and the IP(6(-) )induced (45)Ca(2+) efflux were inhibited by the calmodulin antagonist, trifluoperazine.
authors: Department of Botany, North Carolina State University, Raleigh, North Carolina 27695.
authors: M
authors: M
authors: Rincon
authors: W F
authors: WF
authors: Boss