Biochemical Basis of Variability in Nitrate Reductase Activity in Wheat (Triticum aestivumL.) Genotypes

摘要

Significant differences in the activity of nitrate reductase in vivo and in vitro were observed among wheat genotypes, when expressed on a dry weight basis. The genotypes with high nitrate reductase (HNR) activity exhibited an efficient nitrate induction system. Availability of NADH seemed to be partially responsible for the low activities of the enzyme in genotypes categorized as low nitrate reductase group (‘LNR). Biochemical analysis of the genotypes revealed that‘HNR’genotype had more active enzyme protein, high rates of enzyme protein synthesis and higher level of steady state nitrate reductase-mRNA relative to those observed in‘LNR