Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 6, 2013
Publication Date: July 23, 2014
Citation: Anderson, O.D. 2014. The spectrum of major seed storage genes and proteins in oats (Avena sativa). PLoS One. DOI: 10.1371/journal.pone.0083569. Interpretive Summary: The oat seed storage proteins are mainly composed of two classes: the avenins and globulins. These are storage for supporting the early stages of germination and early seedling development. Among the major cereals, the globulins are the major seed protein class in rice and oats, and along with the higher protein content of oats is the basis for the relative higher nutrition content in oats compared to the other cereals. The avenins are prolamins – seed proteins high in proline and glutamine amino acids and associated with celiac disease. In spite of their importance, neither the avenins nor the globulins have been completely described. The current report describes a comprehensive analysis of the oat avenin and globulin seed proteins from a single oat cultivar. This more complete description of the major oat seed proteins will allow a more thorough analysis of their contributions to oat seed characteristics related to nutritional value, evolutionary history, and potential celiac association.
Technical Abstract: Using available EST resources for a single oat cultivar, the spectrum of avenin and globulin sequences are described for the gene coding regions and the derived protein sequences. The single oat hexaploid germplasm expresses nine unique avenin sequences divided into 3-4 distinct subclasses, implying about 3 genes per genome. The avenins are shown to have two repetitive regions rich in glutamines and the source of most of the difference in molecular weights among the avenins. The globulins from the same hexaploid germplasm include 24 distinct sequences – implying about 8 sequences per genome. Variation is oat globulin size results mainly from a glutamine-rich domain, similar to as in the avenins, and to variation in the C-terminal sequence domain. In addition to DNA sequence variation for the C-terminal domain, two globulin genes have premature stop codons that shorten the resulting polypeptides by 9 and 17 amino acids. Eight of the globulin sequences form a branch of the globulins not previously reported.