title: Transgenic alfalfa plants expressing AtNDPK2 exhibit increased growth and tolerance to abiotic stresses.
abstract: In this study, we generated and evaluated transgenic alfalfa plants (Medicago sativa L. cv. Xinjiang Daye) expressing the Arabidopsis nucleoside diphosphate kinase 2 (AtNDPK2) gene under the control of the oxidative stress-inducible SWPA2 promoter (referred to as SN plants) to develop plants with enhanced tolerance to various abiotic stresses. We selected two SN plants (SN4 and SN7) according to the expression levels of AtNDPK2 and the enzyme activity of NDPK in response to methyl viologen (MV)-mediated oxidative stress treatment using leaf discs for further characterization. SN plants showed enhanced tolerance to high temperature, NaCl, and drought stress on the whole-plant level. When the plants were subjected to high temperature treatment (42 °C for 24 h), the non-transgenic (NT) plants were severely wilted, whereas the SN plants were not affected because they maintained high relative water and chlorophyll contents. The SN plants also showed significantly higher tolerance to 250 mM NaCl and water stress treatment than the NT plants. In addition, the SN plants exhibited better plant growth through increased expression of auxin-related indole acetic acid (IAA) genes (MsIAA3, MsIAA5, MsIAA6, MsIAA7, and MsIAA16) under normal growth conditions compared to NT plants. The results suggest that induced overexpression of AtNDPK2 in alfalfa will be useful for increasing biomass production under various abiotic stress conditions.
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea; Department of Horticulture, Chungnam National University, Daejeon, Republic of Korea.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Northwest A & F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Li
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon, Republic of Korea.
authors.forename: Qingbo
authors.initials: Q
authors.lastname: Ke
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, 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 305-806, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon, Republic of Korea.
authors.forename: Haeng-Soon
authors.initials: HS
authors.lastname: Lee
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Northwest A & F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Bingcheng
authors.initials: B
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Northwest A & F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Xi-Ping
authors.initials: XP
authors.lastname: Deng
authors.affiliation: Department of Horticulture, Chungnam National University, Daejeon, Republic of Korea.
authors.forename: Yong Pyo
authors.initials: YP
authors.lastname: Lim
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon, Republic of Korea. Electronic address: sskwak@kribb.re.kr.
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Kwak
mesh_terms: D000455:Medicago sativa / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D010269:Paraquat / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature
chemical_list: D010940:Plant Proteins; D012965:Sodium Chloride; D010269:Paraquat
keywords: Alfalfa; AtNDPK2; Biomass; Drought stress; Oxidative stress; SWAP2 promoter; Salt stress