title: Mutations in Durum WheatSBEIIGenes affect Grain Yield Components, Quality, and Fermentation Responses in Rats.
abstract: Increased amylose in wheat (Triticumssp.) starch is associated with increased resistant starch, a fermentable dietary fiber. Fermentation of resistant starch in the large intestine produces short-chain fatty acids that are associated with human health benefits. Since wheat foods are an important component of the human diet, increases in amylose and resistant starch in wheat grains have the potential to deliver health benefits to a large number of people. In three replicated field trials we found that mutations in starch branching enzyme II genes(SBEIIaandSBEIIb) in both A and B genomes (SBEIIa/b-AB) of durum wheat [T. turgidumL. subsp.durum(Desf.) Husn.] resulted in large increases of amylose and resistant starch content. The presence of these four mutations was also associated with an average 5% reduction in kernel weight (P= 0.0007) and 15% reduction in grain yield (P =0.06) compared to the wild type. Complete milling and pasta quality analysis showed that the mutant lines have an acceptable quality with positive effects on pasta firmness and negative effects on semolina extraction and pasta color. Positive fermentation responses were detected in rats (Rattusspp.) fed with diets incorporating mutant wheat flour. This study quantifies benefits and limitations associated with the deployment of theSBEIIa/b-AB mutations in durum wheat and provides the information required to develop realistic strategies to deploy durum wheat varieties with increased levels of amylose and resistant starch.
authors.affiliation: Dep. of Plant Sciences, Univ. of California, Davis, CA 95616.
authors.forename: Brittany
authors.initials: B
authors.lastname: Hazard
authors.affiliation: Dep. of Plant Sciences, Univ. of California, Davis, CA 95616.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Dep. of Plant Sciences, Univ. of California, Davis, CA 95616.
authors.forename: Mahmoudreza
authors.initials: M
authors.lastname: Naemeh
authors.affiliation: Dep. of Anatomy, Physiology and Cell Biology, UC Davis School of Veterinary Medicine, Davis, CA 95616.
authors.forename: M Kristina
authors.initials: MK
authors.lastname: Hamilton
authors.affiliation: Dep. of Nutrition, Univ. of California, Davis, CA 95616.
authors.forename: Bret
authors.initials: B
authors.lastname: Rust
authors.affiliation: Dep. of Anatomy, Physiology and Cell Biology, UC Davis School of Veterinary Medicine, Davis, CA 95616.
authors.forename: Helen E
authors.initials: HE
authors.lastname: Raybould
authors.affiliation: Dep. of Nutrition, Univ. of California, Davis, CA 95616. USDA-ARS, Obesity and Metabolism Research Unit, Western Human Nutrition Research Center, Davis, CA 95616.
authors.forename: John W
authors.initials: JW
authors.lastname: Newman
authors.affiliation: Dep. of Nutrition, Univ. of California, Davis, CA 95616. USDA-ARS, Obesity and Metabolism Research Unit, Western Human Nutrition Research Center, Davis, CA 95616.
authors.forename: Roy
authors.initials: R
authors.lastname: Martin
authors.affiliation: Dep. of Plant Sciences, Univ. of California, Davis, CA 95616. Howard Hughes Medical Institute, Chevy Chase, MD 20815.
authors.forename: Jorge
authors.initials: J
authors.lastname: Dubcovsky