title: The effect of exogenous calcium on mitochondria, respiratory metabolism enzymes and ion transport in cucumber roots under hypoxia.
abstract: Hypoxia induces plant stress, particularly in cucumber plants under hydroponic culture. In plants, calcium is involved in stress signal transmission and growth. The ultimate goal of this study was to shed light on the mechanisms underlying the effects of exogenous calcium on the mitochondrial antioxidant system, the activity of respiratory metabolism enzymes, and ion transport in cucumber (Cucumis sativus L. cv. Jinchun No. 2) roots under hypoxic conditions. Our experiments revealed that exogenous calcium reduces the level of reactive oxygen species (ROS) and increases the activity of antioxidant enzymes in mitochondria under hypoxia. Exogenous calcium also enhances the accumulation of enzymes involved in glycolysis and the tricarboxylic acid (TCA) cycle. We utilized fluorescence and ultrastructural cytochemistry methods to observe that exogenous calcium increases the concentrations of Ca(2+) and K(+) in root cells by increasing the activity of plasma membrane (PM) H(+)-ATPase and tonoplast H(+)-ATPase and H(+)-PPase. Overall, our results suggest that hypoxic stress has an immediate and substantial effect on roots. Exogenous calcium improves metabolism and ion transport in cucumber roots, thereby increasing hypoxia tolerance in cucumber.
authors: Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.|Horticulture Research Institute, Shanghai Academy Agricultural Sciences, Key Laboratory of Protected Horticulture Technology, Shanghai, 201403, China.
authors: Lizhong
authors: L
authors: He
authors: Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Bin
authors: B
authors: Li
authors: Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.|College of Life Science, Anhui Science and Technology University, Fengyang, Anhui 233100, China.
authors: Xiaomin
authors: X
authors: Lu
authors: Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Lingyun
authors: L
authors: Yuan
authors: Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Yanjuan
authors: Y
authors: Yang
authors: Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Yinghui
authors: Y
authors: Yuan
authors: Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Jing
authors: J
authors: Du
authors: Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Shirong
authors: S
authors: Guo
mesh_terms: D002118:Calcium / Q000493:pharmacokinetics*; D015687:Cell Hypoxia / Q000502:physiology; D019069:Cell Respiration / Q000502:physiology; D018553:Cucumis sativus / Q000378:metabolism*; D006867:Hydrolases / Q000378:metabolism*; D017136:Ion Transport / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology; D010100:Oxygen / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D006867:Hydrolases; D010100:Oxygen; D002118:Calcium