|FOGARTY, MELISSA - Brigham Young University|
|SMITH, SCOTT - North Carolina State University|
|SHERIDAN, JAIME - General Mills, Inc|
|ISLAMOVIC, EMIR - Basf Corporation|
|REID, ROBERT - University Of North Carolina|
|JACKSON, ERIC - General Mills, Inc|
|MAUGHAN, PETER - Brigham Young University|
|AMES, NANCY - Agriculture And Agri-Food Canada|
|HSIEH, TZUNG-FU - North Carolina State University|
|JELLEN, ERIC - Brigham Young University|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2019
Publication Date: 2/25/2020
Citation: Fogarty, M.C., Smith, S.M., Sheridan, J.L., Hu, G., Islamovic, E., Reid, R., Jackson, E.W., Maughan, P.J., Ames, N.P., Hsieh, T., Jellen, E.N. 2020. Identification of mixed linkage ß-glucan quantitative trait loci and evaluation of cslF6 homoeologs in hexaploid oat. Crop Science. 60(2):914-933. https://doi.org/10.1002/csc2.20015.
Interpretive Summary: Oat is an important cereal crop that is rich in a dietary fiber called beta-glucan which can benefit human health. The genetic mechanism of beta-glucan biosynthesis is known in barley, but not in oat. Oat is a hexaploid species with three genomes, A, C, and D. In this study we mapped the location of genes associated with beta-glucan synthesis on each of the three genomes and measured their expression. We discovered that the expression of the beta-glucan synthesis gene in oat genome C was negatively correlated with beta-glucan content in grains. Our work increases our understanding of beta-glucan in oat and may help scientists to better increase the content of this beneficial fiber in the future.
Technical Abstract: Hexaploid oat, (Avena sativa L.) is a commercially important cereal crop due in part to (1-3,1-4)-ß-D-glucan (ß-glucan), a hemicellulose important to human health. Cellulose synthase-like (Csl) genes have been shown to contribute to ß-glucan production with CslF6 likely being of major importance. Here we report a Genome Wide Association Study (GWAS) to identify Quantitative Trait Loci (QTL) controlling ß-glucan production in oat. Three panels of elite accessions (Spring, Winter, World Diversity) of oat were grown in multiple North American locations and genotyped using the Oat 6K custom Infinium iSelect BeadChip. Independent GWAS were performed on each set of accessions and locations, with a meta-analysis identifying 58 significantly associated markers. Synteny with the barley genome identified four major regions of interest revealing the CslF and CslH gene families along with UGPase and AGPase as candidate genes. Subgenome-specific expression of the A-, C- and D- AsCslF6 homoeologs revealed that AsCslF6_C is the least expressed in all tissue types and time points, with low ß-glucan varieties recording the highest As CslF6_C expression. Linkage mapping of the homoeologs placed AsCslF6_D on consensus linkage group Mrg02 overlapping with QTL 2.2 and AsCslF6_A on Mrg12 flanked by markers associated with QTL 12.2. Many QTL identified in this study were homoeologous, representing different gene copies duplicated in ancestral genomes, suggesting that multiple homoeologous copies of ß-glucan biosynthesis genes are contributing to the overall phenotype.