Isolation and characterization of the rye Waxy gene.

Complete genomic and cDNA sequences of the Waxy gene encoding granule-bound starch synthase I (GBSSI) were isolated from the rye genome and characterized. The full-length rye Waxy genomic DNA and cDNA are 2767 bp and 1815 bp, respectively. The genomic sequence has 11 exons interrupted by 10 introns. The rye Waxy gene is GC-rich, with a higher GC frequency in the coding region, especially in the third position of the codons. Exon regions of the rye Waxy gene are more conserved than intron regions when compared with the homologous sequences of other cereals. The mature rye GBSSI proteins share more than 95% sequence identity with their homologs in wheat and barley. A phylogenetic tree based on sequence comparisons of available plant GBSSI proteins shows the evolutionary relationship among Waxy genes from rye and other plant genomes. The identification of the rye Waxy gene will enable the manipulation of starch metabolism in rye and triticale.