[The light-induced increase in the activity of NADP(+)-dependent glyceraldehyde-3-phosphate-dehydrogenase : VI. The influence of the nucleus on the effect].

1. In the green alga Acetabularia mediterranea illumination increases the activity of the NADP(+)-dependent glyceraldehyde-3-phosphate dehydrogenase compared with the dark value just as it does in the leaves of higher plants. 2. One day after enucleation of the Acetabularia-cell (by removal of the rhizoids) no enzyme activity is detectable either in dark or in light. Five days after the treatment the dark value of the enzyme activity reaches approximately the level of the intact plants, and illumination again increases the activity. It is concluded that the effect is independent of the presence of the nucleus.