01758naa a2200337 a 450000100080000000500110000800800410001910000190006024501010007926000090018052009200018965000150110965000110112465000230113565000100115865000120116865000140118065000090119465300130120365300140121665300200123065300160125065300110126665300180127765300160129565300090131165300120132065300120133270000240134477300520136810105602019-03-19       1983    bl uuuu     u00u1 u    #d1 aSANTORO, L. G.  aChanges in nitrate reductase activity during development of soybean leaf.h[electronic resource]  c1983  aThe in vivo and in vitro nitrate activities during the ontogeny of the first leaf showed maximum values at the time of maximum rate of leaf expansion. During this phase the changes of the enzyme activity depend on the level of endogenous nitrate in the tissues, which accumulated preferentialy in young leaves. It was shown that the in vitro nitrate reductase instability increases as leaf age progresses, Inclusion of 3% Casein in the enzyme extraction medium significantly improved enzyme activity suggesting that casein could effect the balance between some activating and inactivating component associated with protein molecule. When nitrate was supplied via the petioles of excised leaves it could be demonstrated that old leaves accumulated less nitrate than youngones. In addition it was shown that the nitrate concentration in the leaf the relation between in vivo and in vitro nitrate reductase activities.  aphysiology  aEnzima  aFisiologia Vegetal  aFolha  aNitrato  aReductase  aSoja  aActivity  aAtividade  aDesenvolvimento  aDevelopment  aEnzyme  aInstabilidade  aInstability  aLeaf  aNitrate  aSoybean1 aMAGALHAES, A. C. N.  tZ. Pflazenphysiol. Bd.gv.112, p.113-121, 1983.