title: Overexpression of the sweet potato IbOr gene results in the increased accumulation of carotenoid and confers tolerance to environmental stresses in transgenic potato.
abstract: In a previous study, we have evidenced that the overexpression of the IbOr gene isolated from sweet potato conferred a tolerance activity against salinity and methyl viologen (MV) treatment in transgenic sweet potato calli along with an enhanced carotenoid content. In this study, to further examine the function of the IbOr gene in heterologous organism, we transformed the IbOr gene into potato under the direction of SWPA2 promoter, a strong inducible promoter upon treatment with various environmental stresses. Consistently with our previous study of sweet potato calli, the level of total carotenoid was elevated up to 2.7-fold (38.1 μg g(-1)DW) compared to the non-transgenic control, Atlantic cultivar. However, the composition of carotenoid was not influenced by the overexpression of the IbOr gene since only pre-existing carotenoids in the non-transgenic control including violaxanthin, lutien and β-carotene were elevated at a similar level of total carotenoids. In general, the transcript levels for most of carotenogenesis-related genes were elevated in transgenic tuber, whereas they remained at similar levels in transgenic leaf tissues compared to those of non-transgenic controls. The increased levels of carotenoid content in the leaf or tuber tissue of transgenic lines were correlated with the enhanced tolerance activity against salt- or MV-mediated oxidative stresses and DPPH radical-scavenging activity. Our preliminary results suggest that further investigation is required for the development of a crop tolerant to salinity and other environmental stresses through the overexpression of the IbOr gene.
authors.affiliation: Sancheong Oriental Medicinal Herb Institute, Sancheong, Gyeongnam Province, Republic of Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Goo
authors.affiliation: Department of Agronomy & Medicinal Plant Resources, Gyeongnam National University of Science & Technology, JinJu, Republic of Korea.
authors.forename: Eun-Heui
authors.initials: EH
authors.lastname: Han
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 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), 125 Gwahak-ro, Yuseong-gu, Daejeon, Republic of Korea.
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Kwak
authors.affiliation: Department of Molecular & Cellular Biology, University of Guelph, Guelph, Ontario N1G2W1, Canada.
authors.forename: Jaeju
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Biology Education, College of Education, and Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Kim
authors.affiliation: College of Pharmacy and Research Institute of Life Sciences, Gyeongsang National University, Jinju, Republic of Korea. Electronic address: amj5812@gnu.ac.kr.
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Ahn
authors.affiliation: Department of Agronomy & Medicinal Plant Resources, Gyeongnam National University of Science & Technology, JinJu, Republic of Korea. Electronic address: shinwlee@gntech.ac.kr.
authors.forename: Shin-Woo
authors.initials: SW
authors.lastname: Lee
mesh_terms: D002338:Carotenoids / Q000737:chemistry*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D027723:Ipomoea batatas / Q000235:genetics* / Q000378:metabolism; D018384:Oxidative Stress; D010544:Peroxidases / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D002338:Carotenoids; D010544:Peroxidases; C121547:swpa2 protein, Ipomoea batatas
keywords: Antioxidant activity; Carotenogenesis; Carotenoid; IbOr; Potato