Effects of the wx gene on starch biosynthesis, physicochemical wheat flour properties, and dry noodle quality

Abstract

Wheat starch biosynthesis is influenced by the Wx gene, which may also affect the quality and characteristics of flour and food. In this study, eight near-isogenic Wx wheat lines were bred and used as test materials for analysis of the content and biosynthesis dynamics of starch, and the changes in flour and dry noodle qualities were evaluated. The results showed that the contents and accumulation rates of amylose, amylopectin, and total starch initially increased and then decreased at 20 d after anthesis. Additionally, the three Wx genes examined in this study had varying effects on the amylose content and accumulation rate, in the order of Wx-B1 > Wx-A1 > Wx-D1. Wx genes had only minor effects on amylopectin biosynthesis. Lack of Wx gene expression was expected to affect the physiochemical properties of wheat flour, with the Wx-B1 gene exhibiting the most dramatic effects. Almost all properties except taste, stickiness, and total score of dry noodles decreased following silencing of the Wx-B1 and Wx-D1 genes. Dry noodle qualities deteriorated to different degrees after silencing of one, two, or three Wx genes, and almost no amylose biosynthesis and very poor dry noodle quality were observed in wheat lacking all three Wx genes.