Sucrose phosphate synthase plays a key role in boron-promoted sucrose synthesis in tobacco leaves

Boron (B) is essential for plant growth. The mechanism of B interacting with sucrose transport is not fully understood. In detached tobacco leaves treated with increasing B concentrations, the concentrations of sucrose, glucose, fructose, and starch as well as the activities of sucrose phosphate synthetase (SPS), sucrose synthetase (SS), and a-amylase were quantified. In addition, the expression levels of sucrose transporters (SUT1 and SUT4) were determined. The data presented here suggest that B promotes the sucrose concentration and transport via elevation of SPS activity, decrease of SS activity, and increase of SUT4 expression level.