title: The OsAMT1.1 gene functions in ammonium uptake and ammonium-potassium homeostasis over low and high ammonium concentration ranges.
abstract: Rice (Oryza sativa) grown in paddy fields is an ammonium (NH4+)-preferring crop; however, its AMT-type NH4+transporters that mediate root N acquisition have not been well characterized yet. In this study, we analyzed the expression pattern and physiological function of the OsAMT1.1 gene of the AMT1 subfamily in rice. OsAMT1.1 is located in the plasma membrane and is mainly expressed in the root epidermis, stele and mesophyll cells. Disruption of the OsAMT1.1 gene decreased the uptake of NH4+, and the growth of roots and shoots under both low NH4+and high NH4+conditions. OsAMT1.1 contributed to the short-term (5 min)15NH4+influx rate by approximately one-quarter, irrespective of the NH4+concentration. Knockout of OsAMT1.1 significantly decreased the total N transport from roots to shoots under low NH4+conditions. Moreover, compared with the wild type, the osamt1.1 mutant showed an increase in the potassium (K) absorption rate under high NH4+conditions and a decrease under low NH4+conditions. The mutants contained a significantly high concentration of K in both the roots and shoots at a limited K (0.1 mmol/L) supply when NH4+was replete. Taken together, the results indicated that OsAMT1.1 significantly contributes to the NH4+uptake under both low and high NH4+conditions and plays an important role in N-K homeostasis in rice.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Hongye
authors.initials: H
authors.lastname: Qu
authors.affiliation: Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: ghxu@njau.edu.cn.
authors.forename: Guohua
authors.initials: G
authors.lastname: Xu
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006706:Homeostasis / Q000187:drug effects; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D009928:Organ Specificity; D012275:Oryza / Q000166:cytology / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects
chemical_list: D064751:Ammonium Compounds; D010940:Plant Proteins; D011188:Potassium
keywords: Ammonium; Ammonium transporter; Interaction; Potassium; Rice