Developing Cold-Chipping Potato Varieties by Silencing the Vacuolar Invertase Gene

Accumulation of reducing sugars during cold storage is a persistent and costly problem for the potato (Solanum tuberosum L.) processing industry. High temperature processing of potato tubers with elevated amounts of reducing sugars results in potato chips, fries, and other products that are unacceptable to consumers because of their bitter taste and unappealing dark color. More problematically, such products contain increased amounts of acrylamide, a neurotoxin and a potential carcinogen. We have demonstrated that silencing of the potato vacuolar acid invertase gene VInv can prevent reducing sugar accumulation in cold-stored tubers. Using this approach we developed VInv silencing lines using RNA interference (RNAi) from four potato cultivars grown currently for potato chip production in North America. Accumulation of reducing sugars during cold storage was reduced by similar to 93% or more in all RNAi lines that had > 90% reduction of VInv transcript. Potato chips produced from these lines were light colored and significantly lower in acrylamide than controls. Changes in growth and tuber yield were not associated with VInv suppression using RNAi. We demonstrate that silencing of VInv is an effective approach to control the cold-induced sweetening problem in potato.