Proteome and Nutritional Shifts Observed in Hordein Double-Mutant Barley Lines

Abstract

Lysine is the most limiting essential amino acid in cereals, and efforts have been made over the decades to improve the nutritional quality of these grains by limiting storage protein accumulation and increasing lysine content, while maintaining desired agronomic traits. The single lys3 mutation in barley has been shown to significantly increase lysine content but also reduces grain size. Herein, the regulatory effect of the lys3 mutation that controls storage protein accumulation as well as a plethora of critically important processes in cereal seeds was investigated in double mutant barley lines. This was enabled through the generation of three hordein double-mutants by inter-crossing three single hordein mutants, that had all been backcrossed three times to the malting barley cultivar Sloop. Proteome abundance measurements were integrated with their phenotype measurements; proteins were mapped to chromosomal locations and to their corresponding functional classes. These models enabled the prediction of previously unknown points of crosstalk that connect the impact of lys3 mutations to other signalling pathways. In combination, these results provide an improved understanding of how the mutation at the lys3 locus remodels cellular functions and impact phenotype that can be used in selective breeding to generate favourable agronomic traits.

Characterization of barley (Horduem vulgare) lys3 mutants identifies genes under the regulation of the prolamin-box binding transcription factor and elucidates its role in endosperm promoter methylation during grain development

“…Table 5; Log2FC -1.95). The CslF6 protein was not detected in the proteome of lys3.a double mutants, but signi cant increases were found in proteins related to b-glucan metabolism such as a b-1,3 glucanase II (3HG0319100) and a b-D-glucan exohydrolase isoenzyme (5HG0510650) (Bose et al, 2021). The b-1,3 glucanase II (3HG0319100) gene was upregulated in the lys3.a mutants, but expression was extremely low (< 1 TPM, Sup.…”

Proteome Changes Resulting from Malting in Hordein-Reduced Barley Lines

“…Previous research investigated the impact of suppression of hordeins on the proteome and nutritional shifts in hordein-reduced barley grain samples, using proteomics approaches including SWATH-MS and targeted proteomics. − However, there is a lack of knowledge on the impact of malting on hordein-reduced lines and the mechanism of how the reduction of individual hordein subtype affects malting. In this study, we used the bottom-up proteomics method using the SWATH-MS approach to identify and relatively quantify changes in proteins due to malting in hordein-reduced barley lines and their corresponding malt samples.…”