Effect of nitrogen application on high molecular weight glutenin subunit expression and grain quality of winter wheat

A pot experiment was carried out to study High Molecular Weight Glutenin Subunit (HMW-GS) expression, quality and their relationship in different gluten wheat types at different N-levels, using SDS-PAGE technology. Two wheat cultivars, strong gluten wheat Linyou 145（LY145） and medium gluten wheat Linyou 2018（LY2018）, were used and five rates of N fertilizer were applied (N 0, 0.667, 1.332, 1.998 and 2.664 g/pot, respectively), with randomized block design. The results showed that, nitrogen application increased HMW-GS expression, and the effect on medium gluten wheat was greater than on strong gluten wheat. The effect of nitrogen application on HMW-GS expression with protein composition differed among subunit type of high quality wheat. Correlation coefficients between HMW-GS expression with gliadin and glutenin in strong gluten wheat were both at 1% significance levels and the correlation coefficient with glutenin in medium gluten wheat was at 5% level. HMW-GS expression was positively correlated with processing quality characteristics. HMW–GS expression in strong gluten wheat was significantly correlated with wet gluten content, stability time, sedimentation value and evaluation value, while HMW–GS expression in medium gluten wheat was only significantly correlated with sedimentation value.