Metabolic profiling of highland barley (Hordeum vulgare var. nudum) genotypes

Abstract Highland barley (HB), a valuable crop thriving in challenging conditions on the Qinghai-Tibet Plateau, possesses rich nutrient contents. This study aims to investigate the nutrient profile of HB genotypes and compare the metabolic profiles of three representative genotypes exhibiting high, medium, and low quality. The screening of HB genotypes reveals significant genotype-dependent differences in starch content, protein content, amino acid content, flavonoid content, antioxidant capacity, β-glucan, and γ-aminobutyric acid. The selected genotypes, namely KKDM2021005, ZJDM012, and DCDM2020017, exemplify high, average, and low quality, respectively. Utilizing LC–MS/MS for metabolic profiling, 617 metabolites from 12 major classes, with flavonoids being the most abundant, are identified. Distinct metabolic profiles are observed among the three genotypes, with 262 DAMs for KKDM2021005 versus DCDM2020017, 261 DAMs for KKDM2021005 versus ZJDM012, and 298 DAMs for ZJDM012 versus DCDM2020017. Enrichment analysis of DAMs highlights pathways associated with anthocyanin, phenylpropanoid, flavone and flavonol, and isoflavonoid biosynthesis. Specific DAMs such as l-valine, l-isoleucine, l-leucine, trifolin, spiraeoside, ferulic acid, betanin, cyanidin-3-O-galactoside, and cyanidin-3-O-glucoside, along with others, contribute to the observed quality differences among the genotypes. These findings provide a foundation for further exploration of genotype-specific metabolic profiles to manipulate the quality aspects of HB utilizing the existing gene pool. By enhancing its nutritional value, functional properties, and potential health benefits, HB can receive significant value addition.