title: Enhanced accumulation of carotenoids in sweetpotato plants overexpressing IbOr-Ins gene in purple-fleshed sweetpotato cultivar.
abstract: Sweetpotato [Ipomoea batatas (L.) Lam] is an important root crop that produces low molecular weight antioxidants such as carotenoids and anthocyanin. The sweetpotato orange (IbOr) protein is involved in the accumulation of carotenoids. To increase the levels of carotenoids in the storage roots of sweetpotato, we generated transgenic sweetpotato plants overexpressing IbOr-Ins under the control of the cauliflower mosaic virus (CaMV) 35S promoter in an anthocyanin-rich purple-fleshed cultivar (referred to as IbOr plants). IbOr plants exhibited increased carotenoid levels (up to 7-fold) in their storage roots compared to wild type (WT) plants, as revealed by HPLC analysis. The carotenoid contents of IbOr plants were positively correlated with IbOr transcript levels. The levels of zeaxanthin were ∼ 12 times elevated in IbOr plants, whereas β-carotene increased ∼ 1.75 times higher than those of WT. Quantitative RT-PCR analysis revealed that most carotenoid biosynthetic pathway genes were up-regulated in the IbOr plants, including PDS, ZDS, LCY-β, CHY-β, ZEP and Pftf, whereas LCY-ɛ was down-regulated. Interestingly, CCD1, CCD4 and NCED, which are related to the degradation of carotenoids, were also up-regulated in the IbOr plants. Anthocyanin contents and transcription levels of associated biosynthetic genes seemed to be altered in the IbOr plants. The yields of storage roots and aerial parts of IbOr plants and WT plants were not significantly different under field cultivation. Taken together, these results indicate that overexpression of IbOr-Ins can increase the carotenoid contents of sweetpotato storage roots.
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, University of Science & Technology (UST), Daejeon 305-350, Republic of Korea.
authors.forename: Sung-Chul
authors.initials: SC
authors.lastname: Park
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea.
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, University of Science & Technology (UST), Daejeon 305-350, Republic of Korea.
authors.forename: Seyeon
authors.initials: S
authors.lastname: Park
authors.affiliation: Bioenergy Crop Research Center, National Institute of Crop Science, Rural Development Administration, Muan 534-833, Republic of Korea.
authors.forename: Hyeong-Un
authors.initials: HU
authors.lastname: Lee
authors.affiliation: Bioenergy Crop Research Center, National Institute of Crop Science, Rural Development Administration, Muan 534-833, Republic of Korea.
authors.forename: Joon Seol
authors.initials: JS
authors.lastname: Lee
authors.affiliation: College of Pharmacy and Research Institute of Life Sciences, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Park
authors.affiliation: College of Pharmacy and Research Institute of Life Sciences, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Ahn
authors.affiliation: Department of Biology Education, College of Education, IALS, PMBBRC, Gyeongsang Naional University, Jinju 660-701, Republic of Korea.
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea.
authors.forename: Jae Cheol
authors.initials: JC
authors.lastname: Jeong
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, University of Science & Technology (UST), Daejeon 305-350, Republic of Korea.
authors.forename: Haeng-Soon
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, University of Science & Technology (UST), Daejeon 305-350, Republic of Korea. Electronic address: sskwak@kribb.re.kr.
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Kwak
mesh_terms: D000872:Anthocyanins / Q000378:metabolism*; D053898:Biosynthetic Pathways / Q000235:genetics; D002338:Carotenoids / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D027723:Ipomoea batatas / Q000235:genetics / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D035281:Plant Tubers / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D065146:Zeaxanthins / Q000378:metabolism; D019207:beta Carotene / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D065146:Zeaxanthins; D019207:beta Carotene; D002734:Chlorophyll; D002338:Carotenoids; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D049308:Dioxygenases; C431939:carotenoid cleavage dioxygenase 1; C079232:beta-carotene hydroxylase; C022398:phytoene dehydrogenase
keywords: Anthocyanin; Carotenoid; Orange gene; Sweetpotato; Zeaxanthin