Although metabolites of barley grains have been analyzed, the changes in metabolite abundance and gene expression regulation mechanisms during barley grain development have not been elucidated. Here, we explore the dynamic accumulation patterns of metabolites in barley grains at six different developmental stages by analyzing high-resolution metabolomic and transcriptomic data from Huadamai6 and Huaai11. We detect 986 metabolites and 18,868 co-expressed genes. Meanwhile, we identify 1057 mQTLs associated with 553 metabolites in a double haploid (DH) population derived from these two cultivars, and integrate metabolome, transcriptome, and mQTL information to construct a global co-expression regulatory network of barley grain metabolism. Using this dataset, we excavate transcription factors and structural genes that regulate flavonoid metabolism pathway, and also reveal the complex mechanism of HvC1-1 and HvMYC-1 regulating grain color differentiation in the DH population. Our findings reveal the metabolic regulatory network of barley grains development, and provide valuable resources for future nutritional quality improvement and molecular design breeding of barley.

To learn more about the nutritional composition and health benefits for human consumers of peas, we used a widely targeted metabolomics-based approach to reveal the metabolite components from three main varieties, and a total of 1095 metabolites were identified. A comparison of 487 differentially accumulated metabolites shared among three varieties of fresh and dried peas found most of the amino acids and derivatives were downregulated and most of the lipids and flavonoids were upregulated in dried peas. Furthermore, comparing the main nutrient profiles exclusively showed that there were few differences in free fatty acids, sugars, vitamins, and alkaloids between dried and fresh peas. Peas are especially enriched with B-group vitamins. Through detailed identification and classification, the flavonoid pathway of peas was revealed; a variety of glycosylated derivatives from kaempferol, quercetin, and luteolin were confirmed to be abundant in peas. It was also found that isoflavones are richer in peas than in many other plants, and putatively the isoflavone synthesis pathway originates from liquiritigenin and naringenin. Our study not only offers guidance for understanding the nutritional components of peas, but also provides the basis for healthy diet analysis of the edible value and health benefits of peas.