[Effect of cordycepin on the activation of RNA and protein synthesis at the early inhibition stages of Agrostemma githago embryos].

In embryos of Agrostemma githago pre-rRNA, ribosomal, heterogeneous, and transfer RNA is transcribed at 0 to 3 hrs of inhibition. An essential amount of hnRNA/mRNA is polyadenylated and can be prepared by affinity chromatography on poly(U)-sepharose columns. At very low concentrations of cordycepin synthesis of poly(A)+-RNA is especially inhibited. At increasing concentration of cordycepin the synthesis of ribosomal RNA is inhibited too. According to these results cordycepin is a suitable inhibitor to study the function of post-transcriptional polyadenylation of mRNA at the regulation of early protein synthesis of imbibing Agrostemma embryos. Incorporation of [3H]-leucine into protein occurring from 0 to 3 hrs of inhibition is not remarkably inhibited by cordycepin. These results may indicate that neither synthesis of mRNA nor its polyadenylation nor the polyadenylation of stable mRNA is involved in the regulation of early protein synthesis.