We have screened a lambda gtlO cDNA library synthesized from poly A RNA isolated from carrot somatic embryos to identify genes whose expression was associated with embryogenesis. 200,000 recombinant phage were differentially hyridized with single-stranded, 32P-labelled cDNA synthesized from poly A RNA isoalted from callus cells (1) and from embryos (2) of Daucus carota. This screen identified EMB-1, an mRNA that uniquely accumulates in embryos. The derived amino acid sequence of this clone shows similarity to the Em protein of wheat (3) and the D19 mRNA and protein of cotton (4). These proteins are translated from Lea mRNAs, which accumulate to high levels in very late staged zygotic embryos of wheat and cotton, respectively (3, 5). This is the first report of a Lea protein of group 1(4) accumulating in somatic embryos.
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