At the early stage of grain development (4 -16 days after anthesis), the total amino acid content increased gradually, reached the maximum on the 12-16th day. Then it decreased continually and reached the minimun on the 24th day . After that, it returned to a slow increase until maturity. The percentages of Val, Lys He Asp and Arg decreasd gradually while the percentages of Glu Pro His and Phe increased progressively during the development of the wheat grains. During the course of grain development, the con...