Light-Induced Nuclear Synthesis of Spinach Chloroplast Fructose-1,6-bisphosphatase

Etiolated spinach (Spinacia oleracea L. var Winter Giant) seedlings show a residual photosynthetic fructose-1,6-bisphosphatase activity, which sharply rises under illumination. This increase in activity is due to a light-induced de novo synthesis, as it has been demonstrated by enzyme labeling experiments with ²H₂O and [³⁵S]methionine. The rise of bisphosphatase activity under illumination is strongly inhibited by cycloheximide, but not by the 70S ribosome inhibitor lincocin, which shows the nuclear origin of this chloroplastic enzyme.