
%0 Journal Article
%A Stewart, GR 
%A Shatilov, VR 
%A Turnbull, MH 
%A Robinson, SA 
%A Goodall, R 
%T Evidence That Glutamate Dehydrogenase Plays a Role in the Oxidative Deamination of Glutamate in Seedlings of <I>Zea mays</I>
%J Functional Plant Biology
%D 1995/10/01
%V 22
%N 5
%P 805-809
%K 
%R https://doi.org/10.1071/PP9950805
%U https://www.publish.csiro.au/paper/PP9950805 
%X In order to investigate the role of glutamate dehydrogenase we have compared the metabolism of [15N]glutamate in young seedlings of wild-type and a glutamate dehydrogenase-null mutant of Zea mays. The principal labelled products in roots of wild-type seedlings are the amide nitrogen of glutamine, glutamine-amino nitrogen and ammonium. The incorporation of label into glutamine-amide is markedly inhibited by methionine sulfoximine. In contrast, little or no labelling of glutamine-amide or ammonium occurs in roots of the GDH1-null mutant, the major labelled product is the amino group of asparagine. In shoots of the wild type, 15N is recovered in the amide of glutamine, ammonium, the amino group of asparagine and other amino acids. In mutant shoots, over 75% of the label is recovered in the asparagine-amino group and there is little labelling of glutamine-amide or ammonium. These major differences in glutamate metabolism of wild-type and mutant seedlings are consistent with glutamate dehydrogenase functioning in the direction of oxidative deamination and having a role in protein catabolism of germinating seeds. 
