Density Gradient Localization of Plasma Membrane and Tonoplast from Storage Tissue of Growing and Dormant Red Beet

Abstract
Membranes from homogenates of growing and of dormant storage roots of red beet (Beta vulgaris L.) were centrifuged on linear sucrose gradients. Vanadate-sensitive ATPase activity, a marker for plasma membrane, peaked at 38% to 40% sucrose (1.165-1.175 grams per cubic centimeter) in the case of growing material but moved to as low as 30% sucrose (1.127 grams per cubic centimeter) during dormancy.