Sun Ha Kim, Sung-Chul Park, Haeng-Soon Lee, Jae Cheol Jeong and Sang-Soo Kwak
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Korea
Sweetpotato (Ipomoea batatas (L.) Lam) ranks seventh in annual production among food crops in the world. It is also an alternative source of industrial materials such as starch, ethanol and useful components. Sweetpotao was recently reevaluated as one of the best healthy foods by the nonprofit CSPI (2007) and the best bioethanol crop on marginal lands by USDA (2008), since it contains high levels of various antioxidants such as vitamin C and carotenoids. Despite its importance as the well-being food source, little research has been carried out on sweetpotato antioxidants at the molecular level. In this respect, transgenic sweetpotato with high yields of ß-carotene by down-regulation of β-carotene hydroxylase (CHY-β) and lycopene ε-cyclase (LCY-ε) were successfully generaed. We have recently isolated IbOrange gene responsible for carotenoid accumulation from the orange-fleshed sweetpotato and introduced it into purple-fleshed sweetpotato to produce both anthocyanin and carotenoids in one storage root. In the presentation, our recent results on metabolic engineering of pigment antioxidants in transgenic sweetpotato will be introduced in terms of sustainable development on global marginal lands.
Keywords: Sweetpotato, carotenoid, β-carotene hydroxylase, lycopene ε-cyclase, Orange gene, RNAi.