Contributions of individual and combined Glu-B1x and Glu-B1y high-molecular-weight glutenin subunits to semolina functionality and pasta quality

Wheat glutenin allele 1Ax2∗ improves dough and bread quality without compromising yield

High yield and good quality are two predominant objectives of most of the wheat breeding programs. Modulating HMW-GS composition is an effective approach to improve grain quality without yield penalty. In this study, we first analyzed the background similarity of three near-isogenic lines (NILs) with 1Ax-null, 1Ax1 or 1Ax2∗ alleles in the background of cultivar Xiaoyan-22 at the protein and DNA levels. On this basis, the yield, yield-related agronomic traits, flour, dough, and bread qualities of the three lines were studied in the 2021-2022 and 2022-2023 seasons. The results showed that, compared to the 1Ax-null allele, the grain yield of the 1Ax1 or 1Ax2∗ allele was not changed, and the 1Ax1 allele averagely decreased protein yield by up to 4.9% and dough yield by up to 6.5%. Notably, the grain yield of the 1Ax2∗ allele was higher than that of the 1Ax1 allele. Meanwhile, compared to the 1Ax-null allele, the 1Ax1 allele averagely increased unextractable polymeric protein content (UPP%) by up to 5.8%, and dough stability time by up to 27.8%, which increased specific volume by up to 4.2%, and the 1Ax2∗ allele averagely increased UPP% by up to 24.2% and dough stability time by up to 111.1%, which increased specific volume by up to 14.4%. These findings indicate that introgression of the 1Ax2∗ allele has a potential to increase wheat quality without negatively affecting grain yield, which provides glutenin allele selection for breeding high-yield and high-quality wheat cultivars in the background of wheat cultivar Xiaoyan-22 and other similar cultivars.

Gliadin and glutenin genomes and their effects on the technological aspect of wheat-based products

Wheat is the most important crops worldwide, providing about one-fifth of the daily protein and calories for human consumption. The quality of cereal-based products is principally governed by the genetic basis of gluten (glutenin and gliadin proteins), which exists in a wide range of variable alleles and is controlled by clusters of genes. There are certain limitations associated with gluten characteristics, which can be genetically manipulated. The present review aimed to investigate the correlation between the genetic characteristics of gluten protein components and wheat-based product's quality. According to various references, Glu-B1d (6 + 8), Glu-B1h (14 + 15) and Glu-B1b (7 + 8) are related to higher gluten strength and pasta quality, while, subunits Dx2 + Dy12 and Dx5 + Dy10, are usually present at the Glu-D1 locus in bread wheat, resulted in lower cooked firmness in pasta. Moreover, introducing Gli-D1/Glu-D3 and Glu-D1 loci into durum wheat genomes, causing to provide the maximum values of gluten index in pasta products. 1Dx5 + 1Dy10 alleles determine the level of increase in dough's consistency, elasticity, viscosity, and extensibility quality of baking and appropriate bread loaf volume, while 1Dx2 + 1Dy12 as the alleles associated with poor baking quality, being more suitable for soft wheat/pastry end uses. Bx7, Bx7OE, 1Bx17 + 1By18, 1Bx13 + 1By16, Bx7 + By9 and 1Bx7 + 1By8 at Glu-B1alleles and 1Ax2* found on Glu-A1, augmented dough strength and has positive effects on consistency, extensibility, viscosity, and elasticity of bread dough. Breeding programs by genome editing have made gluten a promoting component for improving cereal-based products.