Effect of hydrogen ion concentration on sucrose leakage from corn scutellum slices: Evidence for two kinds of sucrose pool within the slice

Abstract

Abstract Incubation of corn scutellum slices in HCl concentrations above 0·01 M caused a marked disruption of cell function as evidenced by the copious leakage of sucrose from the tissue, the loss of the tissue's capacity for the synthesis and storage of sucrose from exogenously supplied hexose and the failure of the tissue to store exogenously supplied sucrose. In contrast, treatment of the tissue in 0·01 M HCl both in the presence and the absence of fructose increased the leakage of sucrose without seriously impairing sucrose synthesis. In addition, pretreatment of the slices in 0·01 M HCl did not reduce sucrose synthesis and storage in the presence of exogenous fructose or inhibit the storage of exogenous sucrose. The leakage of sucrose into 0·01 M HCl or 0·01 M HCl plus fructose is not ascribed to a disruption of the plasmalemma but rather to the existence of two pools of stored sucrose within the tissue, one mobile in acid and the other immobile in acid. The location of these pools within the tissue and the movements of sucrose between pools and bathing solution are discussed in relation to previously conceived ideas of cellular compartmentation and observed anatomical features of the scutellum tissue.