CLONING PROLAMIN GENES FROM EXTRA STRONG BREAD WHEAT CV. GLENLEA

Cereal Research Centre, Agriculture and Agri-Food Canada, 195 Dafoe Road, Winnipeg, Manitoba, Canada, R3T 2M9

Bread wheat cultivar Glenlea produces a flour characterized by extremely strong visco-elastic properties. Its protein composition plays a major role in contributing to this desirable strength characteristic. The prolamins include the polymeric HMW and LMW glutenins and the largely monomeric gliadins. We have cloned all five expressed HMW glutenin subunits from cultivar Glenlea as well as the non-expressed Ay subunit. The DNA sequence data has revealed allelic differences with previously cloned and sequenced subunits from the cultivars Cheyenne and Chinese Spring. Several LMW glutenin genes have been cloned and sequenced including at least one clone from each of the m-type, s-type and i-type subunits. Many pseudogenes were also obtained from this family. Similarly, approximately half the clones obtained for alpha-gliadins were uninterrupted sequences while the other half corresponded to pseudogenes. Sequence analyses and gene silencing in all three families of prolamin genes will be discussed.