NAD- and NADP-Linked Glyceraldehyde-3-Phosphate Dehydrogenases in Light- and Dark-Germinated Seeds of Scots Pine (Pinus silvestris)

By means of arsenate in optical tests the occurrence of both NAD- and NADP-linked glyceraldehyde-3-phosphate dehydrogenase activity has been found in embryo and endosperm tissues from Scots pine seeds. By exclusion of arsenate also evidences for the activity of a non-phosphorylating NADP-linked form have been demonstrated. The results are sustained by inhibition experiments. The enzyme activities have been followed principally during the first 24 hours of the germination process and in relation to the germination-controlling light factor. Homogenates from complete seeds and partly also from separated embryo and endosperm tissues have been studied. The predominant activity in both of the tissues was linked to the NAD-form, expressed either on seed (part) or protein basis. No indications for a light-regulation of anyone of these enzymes have been found contrary to findings from other plant materials.