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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Publications at this Location » Publication #315751
Title: Mutations in durum wheat SBEII genes conferring increased amylose and resistant starch affect grain yield components, semolina and pasta quality and fermentation responses in rats

Author
item HAZARD, BRITTANY - University Of California
item ZHANG, XIAOQIN - University Of California
item NAEMEH, REZA - University Of California
item HAMILTON, KRISTINA - University Of California
item RUST, BRET - University Of California
item RAYBOULD, HELEN - University Of California
item Newman, John
item MARTIN, ROY - University Of California
item DUBCOVSKY, JORGE - University Of California

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/14/2015
Publication Date: 6/2/2015
Citation: Hazard, B., Zhang, X., Naemeh, R., Hamilton, K.M., Rust, B., Raybould, H.E., Newman, J.W., Martin, R., Dubcovsky, J. 2015. Mutations in durum wheat SBEII genes conferring increased amylose and resistant starch affect grain yield components, semolina and pasta quality and fermentation responses in rats. Crop Science. 55(6):2813–2825. doi: 10.2135/cropsci2015.03.0179.

Interpretive Summary: Increased amylose in wheat (Triticum spp.) 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 provide 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 consumers. We show here that mutations in SBEIIa and SBEIIb genes in both A and B genomes (SBEIIa/b-AB) of durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] resulted in large increases of amylose and resistant starch content. In three replicated field trials, the presence of these four mutations was associated with an average 5% reduction in kernel weight (P = 0.0007) and 15% reduction in grain yield (P = 0.06) compared to the wildtype. 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. Increased fermentation was detected in the lower intestine of rats fed diets incorporating mutant wheat flour. This study quantifies benefits and costs associated with the deployment of the SBEIIa/b-AB mutations in durum wheat and will help breeders to develop realistic strategies to deploy durum wheat varieties with increased levels of amylose and resistant starch.

Technical Abstract: Increased amylose in wheat (Triticum spp.) 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 provide 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 consumers. We show here that mutations in SBEIIa and SBEIIb genes in both A and B genomes (SBEIIa/b-AB) of durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] resulted in large increases of amylose and resistant starch content. In three replicated field trials, the presence of these four mutations was associated with an average 5% reduction in kernel weight (P = 0.0007) and 15% reduction in grain yield (P = 0.06) compared to the wildtype. 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. Increased fermentation was detected in the lower intestine of rats fed diets incorporating mutant wheat flour. This study quantifies benefits and costs associated with the deployment of the SBEIIa/b-AB mutations in durum wheat and will help breeders to develop realistic strategies to deploy durum wheat varieties with increased levels of amylose and resistant starch.