Dissertation
MOLECULAR CHARACTERIZATION OF THE LOW MOLECULAR WEIGHT GLUTENIN SUBUNIT GENE FAMILY MEMBERS AND THEIR EFFECT ON WHEAT QUALITY
Doctor of Philosophy (PhD), Washington State University
01/2018
Handle:
https://hdl.handle.net/2376/16357
Abstract
Gluten is a macro polymer responsible for the unique viscoelastic properties of wheat dough and it is formed from the interaction of wheat seed storage proteins. The low-molecular-weight glutenin subunits (LMW-GSs) are one of the major components of gluten and play a critical role in the determination of wheat end-use quality. However, a clear association between different LMW-GSs and wheat quality is not well understood. The LMW-GSs are in fact hard to differentiate both at genic and protein level. They are encoded by a multigene family located on the short arm of the homoeologous group 1 chromosomes at the Glu-3 loci. The number of LMW-GS genes in each wheat variety differs and there is evidence that genes at each Glu-3 locus are divided by large intergenic and highly recombinogenic regions. Also, LMW-GSs are highly similar in structure among themselves and with many gliadins making them difficult to differentiate at the protein level. For these reasons, the identification of different LMW-GS protein profiles has been challenging, and conflicting results on the association between LMW-GS alleles and wheat end-use quality have been reported. The objective of this project was to develop a better understanding of the genetics of the LMW-GSs and of the role that each LMW-GS gene has in the determination of wheat end-use quality. First a set of common wheat varieties identified as standards for the Glu-3 alleles were analyzed for their LMW-GS genic profile to verify whether there was an association between a specific genic profile and the relative Glu-3 allele. Then, the genetic linkage between the LMW-GS genes at each Glu-3 locus was investigated to develop a better understanding of the Glu-3 loci structure. The results obtained from the two previous analyses were used to better interpret and characterize the LMW-GS profile of a set of elite bread wheat varieties and to correlate specific LMW-GS genes to different dough rheology parameters. Finally, a set of molecular markers specific for each LMW-GS haplotype was developed to facilitate the analysis of the LMW-GSs in wheat breeding programs. Results of this project will greatly improve the current knowledge of the LMW-GSs.
Metrics
Details
- Title
- MOLECULAR CHARACTERIZATION OF THE LOW MOLECULAR WEIGHT GLUTENIN SUBUNIT GENE FAMILY MEMBERS AND THEIR EFFECT ON WHEAT QUALITY
- Creators
- Maria Itria Ibba
- Contributors
- Craig F. Morris (Advisor)Michael O. Pumphrey (Committee Member)Karen A. Sanguinet (Committee Member)Doreen Main (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Crop and Soil Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 182
- Identifiers
- 99900581821801842
- Language
- English
- Resource Type
- Dissertation