Synthesis and accumulation of the essential amino acids lysine and threonine in seeds

Humans and monogastric animals cannot synthesize ten out of the twenty protein amino acids and therefore should obtain them in the diet. Among the essential amino acids, lysine and threonine are considered exceedingly important, inasmuch as they are among the most limiting essential amino acids in cereal grains, which represent the largest source of food worldwide. Cereal based diets for livestock are routinely supplemented with lysine plus threonine, and such supplements were proven to be of high beneficial value to livestock growth (Bright and Shewry, 1983; Cuaron et aL, 1984; Fuller et aL, 1979).