Our primary objective in looking for nitrate reductase (NR) mutants in soybeans is to attempt to overcome the inhibition of nitrogen fixation by soil nitrate. The rationale depends upon blocking normal nitrate metabolism by finding defective NR mutants, thus liberating additional carbon and ener-gy for use by nodules in nitrogen fixation. Additional benefits likely to result from the isolation of NR mutants in soybeans are a) a better under-standing of normal nitrate metabolism and b) provision of easily selectable genetic markers.
Ryan, Sarah A.; Nelson, Richard S.; and Harper, James E.
"Research Notes : Selection and inheritance of nitrate reductase mutants in soybeans,"
Soybean Genetics Newsletter: Vol. 10
, Article 14.
Available at: http://lib.dr.iastate.edu/soybeangenetics/vol10/iss1/14