Effect of high-lysine mutations on the protein fractions of barley grain.

We have studied the effects of six high-lysine barley mutations (Risø mutants 1508 and 56, Notch 1 and 2, lys 95 and 449) on the protein fractions of the grain. All mutants had a decreased relative and total amount of the lysine-poor hordein fraction, but only in Risø 1508 and 56 was the polypeptide composition of this fraction greatly affected. In all the mutants there were increases in the lysine-rich glutelin proteins and in nonprotein N while in Risø 1508 and the Notch mutants the total amount of salt-soluble proteins was also increased and their relative polypeptide composition substantially altered.