In cotyledons of 4 day old etiolated, dark-induced radish seedlings a high level of nitrate reductase was found after an induction period of 24 hours. The activity declined after a prolonged induction time. It was shown that the decrease in activity was not due to a decrease in uptake of nitrate. In the dark other factors must become limiting after induction periods exceeding 24 hours.

Acta botanica neerlandica

CC BY 3.0 NL ("Naamsvermelding")

Koninklijke Nederlandse Botanische Vereniging

Ineke Stulen, T. Koch-Bosma, & A. Koster. (1973). The influence of light and nitrate on the induction of nitrate reductase in dark grown seedlings of Raphanus sativus. Acta botanica neerlandica, 22(5), 581–588.