Evidence for the involvement of a UDP-glucose-dependent group translocator in sucrose uptake into vacuoles of storage roots of red beet

摘要

Vacuoles isolated from the storage roots of red beet (Beta vulgarisL.) accumulate sucrose via two different mechanisms. One mechanism transports sucrose directly, and its rate is increased by the addition of MgATP. The other mechanism utilizes uridine diphosphate glucose (UDP-glucose) to synthesize and simultaneously transport sucrose phosphate and sucrose into the vacuole. This group translocation mechanism has also been found in sugarcane vacuoles. As in sugarcane, the beet group translocator does not require fructose 6-phosphate, nor is the latter substance transported into the vacuole. The uptake of UDP14Cglucose in inhibited by high concentrations of osmoticum.