Uncovering oat protein diversity following a proteomics approach: A study of 98 genetically diverse varieties grown...

Oat protein components, including albumins, globulins, prolamins, and glutelins, are unique in amino acid composition and techno-functionality. Genetic diversity introduces variation in the relative abundance of these protein components (i.e., protein profile). Selecting oat varieties with desirable protein profiles relevant for food applications requires the screening of a large set of varieties, which could be prohibitive. Therefore, this study uniquely explored the diversity of oat proteins within a large set of samples following a novel, systematic screening approach that combined high-throughput evaluation and bottom-up proteomics. Protein profiling by SDS-PAGE showed key differences in avenins and other protein components of 98 oat varieties grown in two locations, allowing the selection of a smaller subset of samples (n = 53) that represented the diversity of protein profiles. Proteomics analysis of Osborne fractions revealed co-extraction of the different oat protein components. Specifically, globulin proteins were prominently present in the Osborne residual pellet. Accordingly, adjustments were made in the estimation of the relative abundance of the Osborne fractions in the 53 oat samples. The relative abundances of albumin, globulin, prolamin, and glutelin varied significantly (P < 0.05) among these samples. Principal component analysis and clustering effectively mapped differences among the 53 samples, confirming representation of the diversity within the larger set. A smaller subset (n = 10) of samples was selected, with each sample distinctly separated by PCA (P < 0.05). Such streamlined selection could facilitate an in-depth investigation of protein characteristics relevant to food applications, aiding an informed, protein-based selective breeding of oats.