NITROGEN ASSIMILATION IN THE LEGUME ROOT NODULE - CURRENT STATUS OF THE MOLECULAR-BIOLOGY OF THE PLANT ENZYMES

Genes and cDNAs encoding several enzymes in the nitrogen assimilatory pathway have been cloned and characterised from a number of legume species. Molecular studies using these clones have revealed how these genes are regulated to effect changes in the activity of the enzymes in the different cells of the nodule. Current work is addressing the mechanism of the cell-specific expression and metabolic regulation of these genes and is investigating the role of the nitrogen assimilatory enzymes in regulating flux through the nitrogen fixation and assimilation pathways.