title: The enhanced drought tolerance of rice plants under ammonium is related to aquaporin (AQP).
abstract: Previously, we demonstrated that drought resistance in rice seedlings was increased by ammonium (NH4(+)) treatment, but not by nitrate (NO3(-)) treatment, and that the change was associated with root development. To study the effects of different forms of nitrogen on water uptake and root growth under drought conditions, we subjected two rice cultivars (cv. 'Shanyou 63' hybrid indica and cv. 'Yangdao 6' indica, China) to polyethylene glycol-induced drought stress in a glasshouse using hydroponic culture. Under drought conditions, NH4(+) significantly stimulated root growth compared to NO3(-), as indicated by the root length, surface area, volume, and numbers of lateral roots and root tips. Drought stress decreased the root elongation rate in both cultivars when they were supplied with NO3(-), while the rate was unaffected in the presence of NH4(+). Drought stress significantly increased root protoplast water permeability, root hydraulic conductivity, and the expression of root aquaporin (AQP) plasma intrinsic protein (PIP) genes in rice plants supplied with NH4(+); these changes were not observed in plants supplied with NO3(-). Additionally, ethylene, which is involved in the regulation of root growth, accumulated in rice roots supplied with NO3(-) under conditions of drought stress. We conclude that the increase in AQP expression and/or activity enhanced the root water uptake ability and the drought tolerance of rice plants supplied with NH4(+).
authors: Jiangsu Key Lab for Organic Waste Utilization and National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, 210095 China.
authors: Lei
authors: L
authors: Ding
authors: Jiangsu Key Lab for Organic Waste Utilization and National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, 210095 China.
authors: Cuimin
authors: C
authors: Gao
authors: Jiangsu Key Lab for Organic Waste Utilization and National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, 210095 China.
authors: Yingrui
authors: Y
authors: Li
authors: Crop Physiology and Production Center (CPPC), National Key Laboratory of Crop Genetic Improvement, MOA, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors: Yong
authors: Y
authors: Li
authors: Jiangsu Key Lab for Organic Waste Utilization and National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, 210095 China.
authors: Yiyong
authors: Y
authors: Zhu
authors: Jiangsu Key Lab for Organic Waste Utilization and National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, 210095 China.
authors: Guohua
authors: G
authors: Xu
authors: Jiangsu Key Lab for Organic Waste Utilization and National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, 210095 China.
authors: Qirong
authors: Q
authors: Shen
authors: Department of Biology, Applied Plant Sciences, Technische Universität Darmstadt, Schnittspahn Strasse 10, D-64287 Darmstadt, Germany.
authors: Ralf
authors: R
authors: Kaldenhoff
authors: Department of Biology, Applied Plant Sciences, Technische Universität Darmstadt, Schnittspahn Strasse 10, D-64287 Darmstadt, Germany.
authors: Lei
authors: L
authors: Kai
authors: Jiangsu Key Lab for Organic Waste Utilization and National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, 210095 China. Electronic address: sguo@njau.edu.cn.
authors: Shiwei
authors: S
authors: Guo
mesh_terms: D064751:Ammonium Compounds / Q000494:pharmacology*; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism*; D055864:Droughts; D018527:Hydroponics; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D036226:Seedlings / Q000235:genetics / Q000502:physiology; D014867:Water / Q000378:metabolism
chemical_list: D064751:Ammonium Compounds; D020346:Aquaporins; D009566:Nitrates; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D014867:Water; D009584:Nitrogen
keywords: Aquaporin; Drought stress; Ethylene; Hydraulic conductivity; Nitrogen forms; Root growth