Electrophoretic variation in glutamate dehydrogenase and other isozymes in wild carrot cells cultured in the presence and absence of 2,4-dichlorophenoxyacetic acid

Summary Electrophoretic analysis of isozymal differences was performed with extracts of wild carrot (Daucus carota L.) cells, grown in the presence and absence of 2,4-dichlorophenoxyacetic acid (2,4-D). There were no differences in the patterns of malate dehydrogenase, acid phosphatase, aspartate aminotransferase, and γ-glutamyl transferase. Quantitative differences in peroxidase isozymes were detected, the plus 2,4-D cultures having lower activities. Esterase patterns were similar, but there were differences in individual isozyme activities and an additional form present in the minus 2,4-D cells. the greatest differences were in patterns of glutamate dehydrogenase with the minus 2,4-D cultures containing only the slowly migrating isozymes. The changes in glutamate dehydrogenase, as revealed by isozyme changes, together with the requirement for ammonia in embryogenesis, suggests that this enzyme may be associated with differentiation in wild carrot cells.