title: Net ammonium and nitrate fluxes in wheat roots under different environmental conditions as assessed by scanning ion-selective electrode technique.
abstract: Wheat is one of the most important food crops in the world, its availability affects global food security. In this study, we investigated variations in NH4(+) and NO3(-) fluxes in the fine roots of wheat using a scanning ion-selective electrode technique in the presence of different nitrogen (N) forms, N concentrations, and pH levels as well as under water stress. Our results show that the fine roots of wheat demonstrated maximum NH4(+) and NO3(-) influxes at 20 mm and 25 mm from the root tip, respectively. The maximal net NH4(+) and NO3(-) influxes were observed at pH 6.2 in the presence of a 1/4 N solution. We observed N efflux in two different cultivars following the exposure of roots to a 10% PEG-6000 solution. Furthermore, the drought-tolerant cultivar generally performed better than the drought-intolerant cultivar. Net NH4(+) and NO3(-) fluxes may be determined by plant growth status, but environmental conditions can also affect the magnitude and direction of N flux. Interestingly, we found that NO3(-) was more sensitive to environmental changes than NH4(+). Our results may be used to guide future hydroponic experiments in wheat as well as to aid in the development of effective fertilisation protocols for this crop.
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China.
authors.forename: Yangquanwei
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China.
authors.forename: Weiming
authors.initials: W
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China.
authors.forename: Zhouping
authors.initials: Z
authors.lastname: Shangguan
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D018556:Crops, Agricultural / Q000378:metabolism; D004777:Environment; D017736:Ion-Selective Electrodes; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D009589:Nitrogen Oxides / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D014908:Triticum / Q000378:metabolism*
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D009589:Nitrogen Oxides; D000644:Quaternary Ammonium Compounds; D009584:Nitrogen