The appearance of nitrate reductase activity in nitrogen-starved cells of Ankistrodesmus braunii.
Nitrate reductase activity was detectable in ammonium-grown cells of Ankistrodesmus braunii after 50 minutes of nitrogen starvation. The rate of formation of nitrate reductase was stimulated by addition of nitrate and inhibited completely by cycloheximide (20 μg/ml). Nitrogen-starved cells assimilated added nitrate or nitrite rapidly and no nitrite or nitrate was detectable in either cells or culture medium from cultures subjected to nitrogen starvation. It is concluded that nitrate is not obligatory for the formation of nitrate reductase.
Department of Botany and Microbiology, University College, Swansea, U.K..
P J
PJ
Syrett
C R
CR
Hipkin