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Nitrate Reductase Regulation
Nitrate Reductase (NR) is regulated at the transcriptional and translational levels induced by light, nitrate, and possibly a negative feedback mechanism. First, nitrate assimilation is initiated by the uptake of nitrate from the root system, reduced to nitrite by nitrate reductase, and then nitrite is reduced to ammonia by nitrite reductase. Ammonia then goes into the GS-GOGAT pathway to be incorporated into amino acids. When the plant is under stress, instead of reducing nitrate via NR to be incorporated into amino acids, the nitrate is reduced to nitric oxide which can have many damaging effects on the plant. Thus, the importance of regulating nitrate reductase activity is to limit the amount of nitric oxide being produced.

Inactivation of Nitrate Reductase
The inactivation of nitrate reductase has many steps and many different signals that aid in the inactivation of the enzyme. Specifically in spinach, the very first step of nitrate reductase inactivation is the phosphorylation of NR on the 543-serine residue. The very last step of nitrate reductase inactivation is the binding of the 14-3-3 adapter protein, which is initiated by the presence of Mg2+ and Ca2+

Nitrate Reductase in Anoxic Conditions
Studies were done measuring the nitrate uptake and nitrate reductase activity in anoxic conditions to see if there was a difference in activity level and tolerance to anoxia. These studies found that nitrate reductase, in anoxic conditions improves the plants tolerance to being less aerated. This increased activity of nitrate reductase was also related to a increase in nitrite release in the roots. The results of this study showed that the dramatic increase in nitrate reductase in anoxic conditions can be directly attributed to the anoxic conditions inducing the dissociation of 14-3-3 protein from NR and the dephosphorylation of the nitrate reductase