title: Aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference.
abstract: OBJECTIVE
  Acidic soils are dominated chemically by more ammonium and more available, so more potentially toxic, aluminium compared with neutral to calcareous soils, which are characterized by more nitrate and less available, so less toxic, aluminium. However, it is not known whether aluminium tolerance and nitrogen source preference are linked in plants.
  
  
  METHODS
  This question was investigated by comparing the responses of 30 rice (Oryza sativa) varieties (15 subsp. japonica cultivars and 15 subsp. indica cultivars) to aluminium, various ammonium/nitrate ratios and their combinations under acidic solution conditions.
  
  
  RESULTS
  indica rice plants were generally found to be aluminium-sensitive and nitrate-preferring, while japonica cultivars were aluminium-tolerant and relatively ammonium-preferring. Aluminium tolerance of different rice varieties was significantly negatively correlated with their nitrate preference. Furthermore, aluminium enhanced ammonium-fed rice growth but inhibited nitrate-fed rice growth.
  
  
  CONCLUSIONS
  The results suggest that aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference under acidic solution conditions. A schematic diagram summarizing the interactions of aluminium and nitrogen in soil-plant ecosystems is presented and provides a new basis for the integrated management of acidic soils.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Xue Qiang
authors.initials: XQ
authors.lastname: Zhao
authors.forename: Shi Wei
authors.initials: SW
authors.lastname: Guo
authors.forename: Fumie
authors.initials: F
authors.lastname: Shinmachi
authors.forename: Michio
authors.initials: M
authors.lastname: Sunairi
authors.forename: Akira
authors.initials: A
authors.lastname: Noguchi
authors.forename: Isao
authors.initials: I
authors.lastname: Hasegawa
authors.forename: Ren Fang
authors.initials: RF
authors.lastname: Shen
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000535:Aluminum / Q000633:toxicity*; D008954:Models, Biological; D009566:Nitrates / Q000494:pharmacology*; D009584:Nitrogen / Q000494:pharmacology; D012275:Oryza / Q000187:drug effects* / Q000502:physiology*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D012987:Soil
chemical_list: D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D012987:Soil; D000535:Aluminum; D009584:Nitrogen