title: The interactive effects of transgenically overexpressed 1Ax1 with various HMW-GS combinations on dough quality by introgression of exogenous subunits into an elite Chinese Wheat variety.
abstract: Seed storage proteins in wheat endosperm, particularly high-molecular-weight glutenin subunits (HMW-GS), are primary determinants of dough properties, and affect both end-use quality and grain utilization of wheat (Triticum aestivum L). In order to investigate the interactive effects between the transgenically overexpressed 1Ax1 subunit with different HMW-GS on dough quality traits, we developed a set of 8 introgression lines (ILs) overexpressing the transgenic HMW-glutenin subunit 1Ax1 by introgression of this transgene from transgenic line B102-1-2/1 into an elite Chinese wheat variety Chuanmai107 (C107), using conventional crossing and backcrossing breeding technique. The donor C107 strain lacks 1Ax1 but contains the HMW-GS pairs 1Dx2+1Dy12 and 1Bx7+1By9. The resultant ILs showed robust and stable expression of 1Ax1 even after five generations of self-pollination, and crossing/backcrossing three times. In addition, overexpression of 1Ax1 was compensated by the endogenous gluten proteins. All ILs exhibited superior agronomic performance when compared to the transgenic parent line, B102-1-2/1. Mixograph results demonstrated that overexpressed 1Ax1 significantly improved dough strength, resistance to extension and over-mixing tolerance, in the targeted wheat cultivar C107. Further, comparisons among the ILs showed the interactive effects of endogenous subunits on dough properties when 1Ax1 was overexpressed: subunit pair 17+18 contributed to increased over-mixing tolerance of the dough; expression of the Glu-D1 allele maintained an appropriate balance between x-type and y-type subunits and thereby improved dough quality. It is consistent with ILs C4 (HMW-GS are 1, 17+18, 2+12) had the highest gluten index and Zeleny sedimentation value. This study demonstrates that wheat quality could be improved by using transgenic wheat overexpressing HMW-GS and the feasibility of using such transgenic lines in wheat quality breeding programs.
authors.affiliation: The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Chinese National Center of Plant Gene Research (Wuhan) HUST Part, The Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Mao
authors.forename: Yin
authors.initials: Y
authors.lastname: Li
authors.forename: Shasha
authors.initials: S
authors.lastname: Zhao
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Lei
authors.forename: Dandan
authors.initials: D
authors.lastname: Meng
authors.forename: Fengyun
authors.initials: F
authors.lastname: Ma
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.forename: Mingjie
authors.initials: M
authors.lastname: Chen
authors.forename: Junli
authors.initials: J
authors.lastname: Chang
authors.forename: Yuesheng
authors.initials: Y
authors.lastname: Wang
authors.forename: Guangxiao
authors.initials: G
authors.lastname: Yang
authors.forename: Guangyuan
authors.initials: G
authors.lastname: He
mesh_terms: D000483:Alleles; D001947:Breeding; D002681:China; D018506:Gene Expression Regulation, Plant; D005983:Glutens / Q000096:biosynthesis* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000096:biosynthesis / Q000235:genetics; D014908:Triticum / Q000235:genetics / Q000378:metabolism*
chemical_list: D021122:Protein Subunits; D005983:Glutens; C037302:glutenin