Abstract
Glutamate dehydrogenase (GDH) catalyzes the amination of
2-oxoglutarate and the deamination of L-glutamate. After the discovery of glutamate synthesis cycle, the function of GDH has been debated. GDH of Brassica napus consists with a and b subunits that are encoded by two genes (gdh1, 2) and forms seven isoforms (GDH1~7). In this report, we examined to identify signals to change
the isoform patters and determined the expression of a subunit polypeptide and the corresponding gdh2 gene.
SA and JA treatments induced GDH7 significantly. Once, the leaf tissue was wounded, any SA, JA and ethylene inhibitors could not suppress the induction of GDH7. Treatment with SA and JA in acid solution induced GDH7 significantly and the isoenzyme patterns were almost identical to those of protoplasts. Changes in GDH isoenzyme patterns of protoplasts reflected the amount of a subunit and gdh2
mRNA.
