Pharmacological Identification of a Calcium Release Channel in the Endoplasmic Reticulum of Plants

Abstract

Whenever we contract our muscles, we do so because there is an ion channel in the endoplasmic reticulum (ER) that releases calcium from within the ER in response to an action potential. Plants do not have the genes for the animal calcium release channels, but they, nevertheless, release calcium from their ER. When Arabidopsis thaliana is subjected to photostimulation in the ER-chloroplast nexus, a calcium wave is observed in the cytoplasm of the cell. Our hypothesis is that an ER calcium release channel is responsible for the calcium wave. We hypothesize that gadolinium blocks at least one of two suspected calcium release channels involved in the production of the calcium wave following photostimulation. We test these hypotheses by examining which part, if any, of the calcium wave is inhibited by gadolinium.