Preformed Messenger RNAs and Early Wheat Embryo Germination

Area of Science:

• Plant Molecular Biology
• Developmental Biology
• Biochemistry

Background:

• Wheat embryo homogenates were fractionated to isolate RNA.
• Messenger RNA (mRNA) content was measured using in vitro translation and hybridization techniques.
• Preformed mRNAs in dry embryos are distributed between pellet and ribosomal/subribosomal fractions.

Purpose of the Study:

• To investigate the distribution and role of preformed mRNAs in wheat embryo germination.
• To compare nucleotide sequences of different mRNA fractions.
• To understand the temporal regulation of early development in wheat embryos.

Main Methods:

• Fractionation of wheat embryo homogenates into cell fractions.
• RNA extraction and quantification of mRNA content.
• cDNA synthesis from polyribosomal and total RNA.
• Hybridization analysis of cDNA with different mRNA fractions.

Main Results:

• During germination, 25-40% of total mRNA becomes polyribosomal, while 60-75% remains in other fractions.
• No significant sequence differences were found between preformed mRNAs in polyribosomal and non-polyribosomal fractions.
• mRNA composition showed considerable change between 5 hours and 2 days of germination.

Conclusions:

• Preformed mRNAs in wheat embryos are not involved in the temporal regulation of early development.
• These mRNAs primarily facilitate rapid growth resumption upon water exposure.
• The study provides insights into the role of stored maternal mRNA in plant embryogenesis.