Glutamate dehydrogenase in the first leaf of wheat

Glutamate dehydrogenase extracted from wheat leaves ( Triticum aestivum L. cv. Capitole) taken at two different physiological stages was analysed by electrophoretic and immune-chemical techniques. Two NAD-dependent antigens were identified which bear the balk of the glutamate dehydrogenase activity in the two extracts. The first enzyme was found in much larger amounts in young than in senescent leaves and the reverse situation was observed for the second antigen. The possible relationships between this antigenic polymorphism and the heterogeneity detected by isoelectric focusing from the two extracts were investigated. A charge heterogeneity (isoelectric points about 5.7 and 4.8) was found for the first antigen in both extracts. The second antigen appeared homogeneous (isoelectric point about 5.7) at least in senescent leaves. The last result indicates that two quite different antigens appear in the same isoelectric focusing zone.