The localisation of enzymes of nitrogen assimilation in maize leaves and their activities during greening

Abstract
The activities of nitrate reductase (EC1.6.6.1), nitrite reductase (EC 1.6.6.4), glutamine synthetase (EC6.3.1.2), glutamate synthase (EC1.4.7.1) and NAD(P)H-dependent glutamate dehydrogenase (EC 1.4.1.3) were investigated in mesophyll and bundle sheath cells of maize leaves (Zea mays L.). Whereas nitrate and nitrite reductase appear to be restricted to the mesophyll and GDH to the bundle sheath, glutamine synthetase and glutamate synthase are active in both tissues. During the greening process, the activities of nitrate and nitrite reductase increased markedly, but glutamine synthetase, glutamate synthase and glutamate dehydrogenase changed little.