Hordein accumulation in developing barley grains
Ontology highlight
ABSTRACT: The temporal pattern of accumulation of hordein storage proteins in developing barley grains was studied by enzyme-linked immunosorbent assay (ELISA), western blot and liquid chromatography tandem mass spectrometry (LC-MS/MS). Hordein accumulation was compared to the pattern seen for two abundant control proteins, serpin Z4 (an early accumulator) and lipid transferase protein (LTP1, a late accumulator). Hordeins were detected from six days post-anthesis (DPA) and peaked at 30 DPA. Changes in fresh weight indicate that desiccation begins at 20 DPA and by 37 DPA fresh weight had decreased by 35%. ELISA analysis of hordein content, expressed on a protein basis, increased to a maximum at 30 DPA followed by a 17% decrease by 37 DPA. The accumulation of 39 tryptic and 29 chymotryptic hordein peptides representing all classes of hordein was studied by LC-MS/MS. Most peptides increased to a maximum at 30 DPA, and either remained at the maximum or did not decrease significantly. Only five tryptic peptides, members of the related B1- and γ1-hordeins decreased significantly by 21-51% at 37 DPA. Thus, the concentration of some specific peptides wasere reduced while remaining members of the same family were not affected. The N-terminal signal region was removed by proteolysis during co-translation. , evidenced by a notable absence of the predicted peptides despite near complete protein sequence coverage. In addition to a suite of previously characterised hordeins, two novel barley B-hordein isoforms and two avenin-like proteins (ALPs), mapping to wheat low molecular weight glutenins (LMW-GS-like B-hordeins), and two avenin-like proteins (ALPs) sharing homology with wheat ALPs, were identified. These identified isoforms have not previously been mapped in the barley genome. Cereal storage proteins provide significant nutritional content for human consumption and seed germination. In barley, the bulk of the storage proteins are due tocomprise the hordein family and the final hordein concentration affects the quality of baked and brewed products. Hordeins are members of the gluten protein family and consumption can trigger health conditions such as coeliac disease, non-coeliac gluten sensitivity, and gluten allergy. It is therefore important to study the accumulation of these proteinshordeins as this knowledge may assist plant breeding for improved health outcomes (by minimizing triggering of detrimental immune responses), nutrition and food reduced coeliac reactivity.processing properties.
INSTRUMENT(S): TripleTOF 5600
ORGANISM(S): Hordeum Vulgare (barley)
TISSUE(S): Endosperm
SUBMITTER: Michelle Colgrave
LAB HEAD: Michelle Lisa Colgrave
PROVIDER: PXD013331 | Pride | 2019-04-18
REPOSITORIES: Pride
ACCESS DATA