Stimulation of membrane-associated polysaccharide synthetases by a membrane potential in developing cotton fibers.

Abstract

Conditions which induce a transmembrane electrical potential, positive with respect to the inside of membrane vesicles, result in a substantial (4-12-fold) stimulation of the activity of membrane-associated β-glucan synthetases in a membrane preparation derived from the developing cotton (Gossypium hirsutum L.) fiber. Induction of electrical potentials which are negative with respect to the inside of the membrane vesicle results in little or no stimulation of β-glucan synthesis. Those products whose synthesis is stimulated are mainly β-1,3-glucan, but there is also a considerable increase in β-1,4-glucan. No α-1,4-glucan (starch) was detected in the reaction products. A transmembrane pH grad..