Ectopic expression of a tobacco invertase inhibitor homolog prevents cold-induced sweetening of potato tubers

We have transformed potato with Nt-inhh cDNA, encoding a putative vacuolar homolog of a tobacco cell wall invertase inhibitor, under the control of th e CaMV 35S promoter. In transgenic tubers, cold-induced hexose accumulation was reduced by up to 75%, without any effect on potato tuber yield. Proces sing quality of tubers was greatly improved without changing starch quantit y or quality, an important prerequisite for the biotechnological use of Nt- inhh for potato transformation.