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The α-amylase activity of cultivated barley is critically important to the brewing industry. Here, we surveyed variation in malt α-amylase activity in 343 cultivated barley accessions from around the world. Population structure analysis based on genotype data at 1536 SNPs clustered these accessions into two groups, one comprising South-East Asian and Ethiopian accessions and one group containing the other accessions. A genome-wide association study identified significant quantitative trait loci (QTLs) for α-amylase activity on all seven chromosomes of barley. Accessions showing high and low α-amylase activity were crossed with the high-quality Japanese malting barley cv. Harun Nijo to develop F mapping populations. We identified two QTLs on chromosome 6H in a cross between Haruna Nijo (high activity) × Weal (highest activity). Single QTLs were identified each on 3H, 4H, and 5H from a cross between Haruna Nijo (high activity) × VLB-1 (low activity), indicating that the high α-amylase activity in Haruna Nijo might be derived from loci on these chromosomes. The addition of the high α-amylase activity QTL alleles from chromosome 6H in cv. Weal further increased the α-amylase activity conferred by alleles of Haruna Nijo. These results demonstrate that a target haplotype can be successfully improved using a strategy comprising diversity analysis of ex situ collections followed by introducing effective new alleles. [ABSTRACT FROM AUTHOR]

Traits conferring brewing quality are important objectives in malting barley breeding. Beer foam stability is one of the more difficult traits to evaluate due to the requirement for a relatively large amount of grain to be malted and then the experimental costs for subsequent brewing trials. Consequently, foam stability tends to be evaluated with only advanced lines in the final stages of the breeding process. To simplify the evaluation and selection for this trait, efficient DNA makers were developed in this study. Previous studies have suggested that the level of both of the foam-associated proteins Z4 and Z7 were possible factors that influenced beer foam stability. To confirm the relationship between levels of these proteins in beer and foam stability, 24 beer samples prepared from malt made from 10 barley cultivars, were examined. Regression analyses suggested that beer proteins Z4 and Z7 could be positive and negative markers for beer foam stability, respectively. To develop DNA markers associated with contents of proteins Z4 and Z7 in barley grain, nucleotide sequence polymorphisms in barley cultivars in the upstream region of the translation initiation codon, where the promoter region might be located were compared. As a result, 5 and 23 nucleotide sequence polymorphisms were detected in protein Z4 and protein Z7, respectively. By using these polymorphisms, cleaved amplified polymorphic sequence (CAPS) markers were developed. The CAPS markers for proteins Z4 and Z7 were applied to classify the barley grain content of 23 barley cultivars into two protein Z4 (pZ4-H and pZ4-L) and three protein Z7 (the pZ7-H, pZ7-L and pZ7-L2) haplotypes, respectively. Barley cultivars with pZ4-H showed significantly higher levels of protein Z4 in grain, and those with pZ7-L and pZ7-L2 showed significantly lower levels of protein Z7 in grain. Beer foam stability in the cultivars with pZ4-H and pZ7-L was significantly higher than that with pZ4-L and pZ7-H, respectively. Our results indicate that these CAPS markers provide an efficient selection tool for beer foam stability in barley breeding programs. [ABSTRACT FROM AUTHOR]

This study investigated whether the consumption of a diet in which high-beta-glucan barley replaced rice would reduce the visceral fat area as well as the serum low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) in hypercholesterolemic Japanese men. A randomized, double-blinded, placebo-controlled intervention study was conducted in 44 hypercholesterolemic Japanese men with a body mass index (BMI) >22 kg/m2. The subjects were randomly assigned to groups consuming either rice (placebo group) or a mixture of rice and pearl barley with a high beta-glucan content (test group, 7.0 g beta-glucan per day) for 12 weeks. Blood samples were taken, and CT scan obtained before the trial and every four weeks during the trial. The pearl barley intake significantly reduced serum concentrations of LDL-C (P = 0.041) and TC (P = 0.037) during the trial. Significant differences between the test and placebo groups were found for the visceral fat (P = 0.039), BMI (P = 0.015), and waist circumference (P = 0.011) at the end point. The consumption of pearl barley with a high beta-glucan content reduces not only LDL-C but also visceral fat area. [ABSTRACT FROM AUTHOR]

This study investigated whether the consumption of a diet in which high-β-glucan barley replaced rice would reduce the visceral fat area as well as the serum low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) in hypercholesterolemic Japanese men. A randomized, double-blinded, placebo-controlled intervention study was conducted in 44 hypercholesterolemic Japanese men with a body mass index (BMI) >22 kg/m2. The subjects were randomly assigned to groups consuming either rice (placebo group) or a mixture of rice and pearl barley with a high β-glucan content (test group, 7.0 g β-glucan per day) for 12 weeks. Blood samples were taken, and CT scan obtained before the trial and every four weeks during the trial. The pearl barley intake significantly reduced serum concentrations of LDL-C (P=0.041) and TC (P=0.037) during the trial. Significant differences between the test and placebo groups were found for the visceral fat (P=0.039), BMI (P= 0.015), and waist circumference (P=0.011) at the end point. The consumption of pearl barley with a high β-glucan content reduces not only LDL-C but also visceral fat area. [ABSTRACT FROM AUTHOR]

High-temperature induction of male sterility during floral organogenesis is a critical problem for barley ( Hordeum vulgare L.) crops that the molecular basis is incompletely understood. Gene expression and differentiation of anthers were examined under normal (20°C day/15°C night) and elevated (30°C day/25°C night) temperatures. Serial analysis of gene expression analysis displayed contrasting profiles of gene expression in early panicles between control and high-temperature conditions. Several transcripts dramatically upregulated before development and differentiation of anther wall layers in normal temperatures, including histone H3, H4 and glycine-rich RNA-binding protein genes, were not upregulated at elevated temperatures and typically abundant mRNAs, such as 60S ribosomal protein L27a and glyoxalase I, appeared to be downregulated. Instead, development and differentiation of tapetum cells and pollen mother cells were completely aborted. Failure of transcriptional reactivation with return to normal temperatures increases with duration of elevated temperatures and is strongly correlated with observation of male sterility. Hyper-phosphorylation of the ser-5 residue of the C-terminal domain of the largest subunit of RNA polymerase II (RPB1) was noted to occur under high-temperature conditions. These results indicate that early development and differentiation of barley anthers are very sensitive to high-temperature stress causing major alterations in gene expression. [ABSTRACT FROM AUTHOR]

The genetic improvement of enzymes important in the brewing process is one of the main goals of barley biotechnology. For the improvement of β-amylase thermostability in barley seeds, we have already constructed a mutant thermostable β-amylase gene, using site-directed mutagenesis and random mutagenesis to achieve the substitution of seven amino acids of the original barley β-amylase. This sevenfold-mutant barley β-amylase showed a thermostability increased by 11.6 °C compared to the original enzyme. In the present article, a thermostable β-amylase gene under the control of the barley β-amylase promoter was introduced to barley protoplasts, and fertile plants were generated from 9 independent transgenic lines. Subsequent analyses indicated that the thermostable β-amylase gene was expressed and β-amylase activity derived from both native and modified genes was detected in the seeds of 6 transgenic lines. The transgene was stably transmitted to progeny, and thermostable β-amylase was synthesized in T4 seeds, demonstrating that our strategy is applicable for the improvement of seed quality for industrial utilization. [ABSTRACT FROM AUTHOR]

With the aim of the development of a culture method for efficient plant regeneration from barley ( Hordeum vulgare L.) protoplasts, we examined several culture conditions for primary calli from immature embryos of cvs. Dissa and Igri, which were used for initiation of cell suspensions. Among the primary callus culture conditions tested, growth condition of donor plants had a great impact on these efficiencies; Igri protoplasts derived from embryos of plants grown in a greenhouse gave rise to albino plants and few green shoots while several cell lines originating from embryos of plants grown in a growth chamber (16h light, 12°C) yielded protoplasts developing into green plants. In contrast, cell suspensions were produced at higher frequencies from calli derived from embryos of greenhouse-grown Dissa plants. In Igri, increased levels of 2,4-dichlorophenoxyaceticacid (2,4-D) significantly reduced the efficiency of cell suspension establishment and plant regeneration from protoplasts was achieved only with suspension cells derived from calli induced at the lowest level (2.5 mg/l), while the effect of the 2,4-D concentration was not clear in Dissa. The developmental stage of immature embryos also affected the efficiency of cell suspension establishment, and the optimal embryo size was determined to be approximately 1mm in diameter. These results demonstrate the importance of callus induction conditions for successful barley protoplast culture. [ABSTRACT FROM AUTHOR]