THE ASSIMILATION OF NITRATE AND AMMONIUM BY CHLAMYDOMONAS REINHARDI

Nitrate assimilation in Chlamydomonas.

Steady state analysis of nitrate-ammonium assimilation by phytoplankter? 2

The ammonium:nitrate delivery ratio to cells of Dunaliella tertiolecta in continuous culture had no effect on the ambient nitrate concentrations at steady state, indicating that the assimilation of these radicals is competitive, not suppressive, under nitrogen limiting conditions. The physiological parameters, C : cell and Chl: cell, were invariant over the range of delivery ratios. Cellular gr...

Cytochrome and Alternative Pathway Respiration during Transient Ammonium Assimilation by N-Limited Chlamydomonas reinhardtii.

Mass spectrometric analysis of gas exchange in light and dark by N-limited cells of Chlamydomonas reinhardtii indicated that ammonium assimilation was accompanied by an increase in respiratory carbon flow to provide carbon skeletons for amino acid synthesis. Tricarboxylic acid (TCA) cycle carbon flow was maintained by the oxidation of TCA cycle reductant via the mitochondrial electron transport...

Nitrate Reductase from a Mutant Strain of Chlamydomonas reinhardii Incapable of Nitrate Assimilation

Nitrate reductase from mutant 305 o f Chlamydomonas reinhardii has been purified about 90-fold and biochemically characterized. The enzyme can use reduced flavins and viologens as electron donors to reduce nitrate but, unlike the nitrate reductase com plex from its parental wild strain, lacks NAD(P)H-nitrate reductase and NAD(P)H-cytochrom e c reductase activities, does not bind to Blue-Agarose...

Root respiration associated with ammonium and nitrate absorption and assimilation by barley.

We examined nitrate assimilation and root gas fluxes in a wild-type barley (Hordeum vulgare L. cv Steptoe), a mutant (nar1a) deficient in NADH nitrate reductase, and a mutant (nar1a;nar7w) deficient in both NADH and NAD(P)H nitrate reductases. Estimates of in vivo nitrate assimilation from excised roots and whole plants indicated that the nar1a mutation influences assimilation only in the shoot...