Preformed Messenger RNAs and Early Wheat Embryo Germination

Wheat (Triticum aestivum L.) embryo homogenates have been fractionated into three cell fractions from which RNA was extracted and assayed for mRNA content by in vitro translation and by ³H]polyuridylic acid hybridization. In dry embryos the preformed mRNAs are distributed equally between a rapidly sedimenting “pellet” fraction and a cytoplasmic “ribosomal/subribosomal” fraction. During germination 25 to 40% of the total mRNA becomes polyribosomal. The remaining 60 to 75% is retained in the pellet and ribosomal/subribosomal fractions.