Regulation of nitrite reduction

This paper addresses the regulation of nitrite reductase (NiR) synthesis. It is contented that NO3- enhances production of NiR at the transcriptional level whereas the light effect appears to be exerted at the translational level. This will have to be confirmed in studies in which polyA RNA isolated from illuminated NO3- treated and control plants is used to direct the synthesis of NiR in a wheat germ translational system. The successful use of polyA RNA to direct in vitro synthesis of NiR will ultimately provide a means for preparation of cDNA for NiR. The availability of such cDNA will allow for the quantification of mRNA for NiR in plants subjected to the various environmental perturbations. Furthermore, by using cDNA as a probe to quantify mRNA levels, it should be possible to assess to what extent genetic variability in NiR levels is controlled at the transcriptional level. 24 refs., 8 figs., 2 tabs