Characterization of high‐molecular‐weight glutenin subunit genes fromElytrigia elongata

Three high‐molecular‐weight glutenin subunit (HMW‐GS) genes fromElytrigia elongata(Host) Nevski were characterized by determining the coding sequences of two x‐type subunit genesEe2.1andEe1.9, and one y‐type subunit geneEe1.8with 2082, 1938 and 1788 bp, respectively. The numbers of amino acids in the central repeat domains of Ee2.1, Ee1.9 and Ee1.8 were considerably fewer than the other known HMW‐GSs with substitutions, insertions and/or deletions involving a single or more amino acid residues. Moreover, an extra cysteine (Cys) was found in the repeated domain of x‐type subunit Ee2.1. The difference in the number and position of Cys residues might be associated with the good dough quality. The extra Cys in the good‐quality subunit Dx5 was at the beginning of the repetitive domain, while the extra Cys in Ee2.1 was at the central repetitive domain. Evolutionary relationships between the HMW‐GSs fromE. elongataand the known HMW‐GSs were estimated. It transpired that Ee1.9, Ee2.1 and Bx7 were clustered into one subgroup with high bootstrap values, while Ee1.8 was closely related to Ay.