K-Box Sequence of the Apetala1-Class MADS-Box Genes in Hexaploid Wheat

Direct amplification of genomic DNA from four wheat species produced DNA fragments corresponding to the K-box sequence of the apetala1/squamosa class of the MADS-box genes. Exons 3 to 5 were highly conserved within the tribe Triticeae and very similar to the apetala1 genes of darnel ryegrass, rice, and maize. Most of the variations observed were due to synonymous substitutions: the deduced amino acid sequences were 89–99% similar within the Triticeae and 88–94% within the entire family Poaceae. Introns 3 and 4 of the apetala1 class genes were similar in wheat and rye and differed from those in other MADS-box genes presently known.