The molecular basis of ammonium transporters in plants MOLECULAR CLONING AND FUNCTIONAL ANALYSIS OF AMMONIUM TRANSPORTERENCODING GENES AMTB IN ASSOCIATIVE NITROGEN-FIXING BACTERIUM PSEUDOMONAS STUTZERI A1501 Effects of Nitrogen Rate on Plant Growth of Autumn Potato Crop and Gene Expression of Nitrate Reductase and Ammonium Transporter Effects of Nitrogen Rate on Plant Growth of Autumn Potato Crop and Gene Expression of Nitrate Reductase and Ammonium Transporter