title: Expression of both CuZnSOD and APX in chloroplasts enhances tolerance to sulfur dioxide in transgenic sweet potato plants.
abstract: We have previously reported that transgenic sweet potato (Ipomoea batatas) plants overexpressing both CuZn superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) under the control of a stress-inducible SWPA2 promoter in chloroplasts (referred to as SSA plants) showed increased resistance to methyl viologen-mediated oxidative stress and chilling. To investigate whether SSA plants show enhanced tolerance to air pollutants, they were exposed to 500ppb of sulfur dioxide (SO2). SO2 caused visible damage to the leaves of sweet potato, but damage in the leaves of non-transgenic (NT) plants was more severe than in those of SSA plants. The photosynthetic activity (Fv/Fm) of the SSA plants decreased by only 7% on the 5th day after the treatment, whereas that of NT plants severely decreased by 63% after 5days of recovery. Moreover, the chlorophyll content in the oldest leaf of NT plants decreased by 69%, whereas that of SSA plants remained at a high level. APX activity in NT plants increased about three times under an SO2 stress, and in SSA plants about five times compared to the case with no stress conditions. These results suggest that the overexpression of both CuZnSOD and APX in chloroplasts reduces the oxidative stress derived from SO2.
authors.affiliation: Department of Biology Education, College of Education, Gyeongsang National University, IALS, 501 Jinju-Daero, Jinju 660-701, Republic of Korea. Electronic address: cefle@gnu.ac.kr.
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), 111 Gwahangno, Yusong-gu, Daejeon 305-806, Republic of Korea.
authors.forename: Soon
authors.initials: S
authors.lastname: Lim
authors.affiliation: Department of Forest Genetic Resources, Korea Forest Research Institute, Suwon 441-350, Republic of Korea.
authors.forename: Sim-Hee
authors.initials: SH
authors.lastname: Han
authors.affiliation: Department of Plant Medicine, IALS, Gyeongsang National University, Jinju 660-751, Republic of Korea.
authors.forename: Jeung Joo
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Biology Education, College of Education, Gyeongsang National University, IALS, 501 Jinju-Daero, Jinju 660-701, Republic of Korea.
authors.forename: Ki Jung
authors.initials: KJ
authors.lastname: Nam
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 111 Gwahangno, Yusong-gu, 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), 111 Gwahangno, Yusong-gu, Daejeon 305-806, 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), 111 Gwahangno, Yusong-gu, Daejeon 305-806, Republic of Korea. Electronic address: sskwak@kribb.re.kr.
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Kwak
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D060387:Ascorbate Peroxidases / Q000096:biosynthesis*; D002734:Chlorophyll / Q000096:biosynthesis; D002736:Chloroplasts / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D027723:Ipomoea batatas / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress / Q000235:genetics; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics*; D013458:Sulfur Dioxide / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000096:biosynthesis*
chemical_list: D000393:Air Pollutants; D013458:Sulfur Dioxide; D002734:Chlorophyll; D060387:Ascorbate Peroxidases; D013482:Superoxide Dismutase
keywords: Ascorbate peroxidase; Oxidative stress; Stress-inducible promoter; Sulfur dioxide; Superoxide dismutase; Sweet potato