Department of Genetics, Harvard Medical School, Boston, MA.
We have isolated two nitrate reductase genes and their corresponding cDNAs from Arabidopsis thaliana. Sequences of the two cDNAs, when compared to a sequence of a barley cDNA clone, confirm their identity as nitrate reductase clones and show that they are closely related. The two genes have been mapped using restriction fragment length polymorphisms; gNR2 is close to the previously identified chl-3 locus and is probably identical to it, while gNR1 maps to a new locus (NIA1) on chromosome 1, near gl-2.