Evidence for a photoinduced synthesis of poly(A) containing mRNA in Fusarium aquaeductuum.

Based on inhibitor studies it has been concluded that in photoregulated processes of plant development, light induces differential gene expression. Using affinity chromatography of double labelled polysomal RNA on poly(U)-sepharose 4B, we were able to demonstrate different (3)H/(14)C ratios for the bound poly(A) containing fraction (mRNA) when compared with the unbound fraction: when [(3)H]uridine was present in the light induced sample and [(14)C]uridine in the dark control, in the bound material the (3)H/(14)C ratio was found to be higher than in the unbound fraction and vice versa. No such shift was observed, when both sample and control were kept in the dark. Our data are interpreted to provide evidence for photoinduced de novo synthesis of mRNA.