Genotypic variation for nitrogen uptake and assimilation using hydroponic culture technique in wheat

Hydroponic culture technique is an alternative way of studying nitrogen metabolism. In this study, the response of six wheat genotypes (PBW 621, PBW 636, GLU 1356, BW 8989, GLU 700, and PBW 343) with respect to nitrogen-metabolizing enzymes in relation to accumulation of soluble proteins and amino acids at two concentrations of nitrogen (2 and 6 mM) was studied. Activities of nitrate reductase (NR) and glutamine synthetase as well as soluble proteins, amino acids, and nitrogen content increased in all six genotypes with increasing concentration of nitrogen in roots as well as shoots. Shoots maintained higher activities of NR and glutamine synthetase; apparently contents of soluble protein, amino acid, and nitrogen were also higher. The upregulation of NR and glutamine synthetase activities with increased concentration of nitrogen possibly contributes to higher nitrogen assimilation efficiency of three genotypes (PBW 621, PBW 636, and GLU 1356) compared to other genotypes.