Environmental impacts on barley grain composition and longevity.

To counter projected reductions in yields of the major crop barley, it is essential to elucidate the mechanisms of its resilience. To assist such efforts, we collected grains from plants grown in fields at 12 testing stations, with suitable temperature and precipitation gradients for identifying environmentally induced changes in their protein and metabolite contents. We then subjected the grains to detailed molecular analysis. The results showed that numerous metabolites and at least a quarter of the grain protein content was modulated by the environment, and provided insights into barley seed production under abiotic stress, including alterations in ribosomal proteins, heatshock protein 70 family proteins, inhibitors, storage proteins, and lipid droplet formation. Potential positive and negative markers of yield were also identified, including the phenolic compound catechin and storage protein levels, respectively. Complementary analyses of barley seedlings and Arabidopsis seeds, respectively, confirmed the role of the identified proteins in abiotic stress responses and highlighted evolutionarily conserved mechanisms. In addition, accelerated ageing experiments revealed that variations in the environment had stronger effects on seed longevity than the genotype. Finally, seeds with the highest longevity differed from the others in gibberellin contents, H2O2 metabolism, and levels of >250 proteins, providing novel targets for improving resilience.

Comparative de novo transcriptome analysis of barley varieties with different malting qualities.

Barley is one of the most important crops in the world. Barley is used as both food and feed and is important for malt production. Demands for malting quality differ among countries and customs. Malting quality is a complex characteristic involving barley genetics, the environmental conditions during barley growth, and the technological parameters of the malting process. In this study, the hypothesis was that there were no differences between two groups of barley varieties with different but defined malting qualities, which was tested using RNA sequencing during selected stages of malting. In total, 919 differentially transcribed genes between the two barley groups were identified and annotated. Differentially expressed genes (DEGs) were primarily assigned to gene ontology (GO) terms of oxidation-reduction process - oxidoreductase activity, response to stress, carbohydrate metabolic process, and proteolysis - hydrolase activity, and metal ion binding. Genes connected with the plasma membrane and its integral components also play important roles in malting quality. DEG profiles of selected genes in the three malting stages indicate a complex character of malting quality. Many single-nucleotide polymorphisms (SNPs) and insertions and deletions (indels) were identified. SNPs and indels with the best quality were used for primer design. After optimization and validation, five molecular markers were developed for use in barley breeding.

Changes in polyphenol compounds and barley laccase expression during the malting process.

BACKGROUND: Polyphenols and phenolic acid are able to slow down or prevent oxidation processes and are therefore thought to have important effects in malting and brewing. Laccase catalyses the oxidation of a wide variety of substrates, including polyphenols. The aim of this paper was to determine the changes in polyphenol compounds and the relative expression of the HvLac1 gene during malting. RESULTS: The dominant phenolic acid was ferulic acid. The amount of ferulic acid increased, whereas the amount of vanillic acid decreased during malting. The highest levels of expression of the HvLac1 gene were observed during the third air rest period in varieties with the 'Haruna Nijo' (HN) allele, as recommended for the production of beer with the protected geographical indication (PGI) 'Ceske pivo' (Czech beer), whereas the highest expression was observed in the first day of germination in varieties with the 'Morex' (M) allele. However, the profiles of HvLac1 gene expression in varieties with alternative alleles during malting were similar, and the level of polyphenol compounds throughout malting was different. CONCLUSION: The polyphenol contents in barley increased several-fold during malting, and the degree of increase differed with variety. The expression of HvLac1 transcript was similar in every barley variety.