Comparison of 4-Mercapto-4-methylpentan-2-one contents in hop cultivars from different growing regions

Contributions of hop-derived thiols were examined. Extremely strong fruity, black currant-like aromas were detected in beers hopped with some U.S. cultivars. 4-Mercapto-4-methylpentan-2-one (4MMP) was supposed to be the main contributor to the fruity aroma, and the contents between cultivars were investigated. In hop pellets, a negative correlation between 4MMP concentration and copper ion content in hops was observed. 4MMP was detected only in U.S., Australian, and New Zealand cultivars, but no European ones, which are treated with copper-containing fungicides (Bordeaux mixture) and therefore have a high content of copper ions. The 4MMP content was highest in Simcoe cultivars, followed by Summit, Apollo, Topaz, Cascade pellets, and also differed between crop years. It was indicated that most 4MMP exists freely in wort or in hop pellets with only small amounts formed from precursors and that the amounts increased during the fermentation process.     

Sat-BSA: an NGS-based method using local de novo assembly of long reads for rapid identification of genomic structural variations associated with agronomic traits

Advances in next generation sequencing (NGS)-based methodologies have accelerated the identifications of simple genetic variants such as point mutations and small insertions/deletions (InDels). Structural variants (SVs) including large InDels and rearrangements provide vital sources of genetic diversity for plant breeding. However, their analysis remains a challenge due to their complex nature. Consequently, novel NGS-based approaches are needed to rapidly and accurately identify SVs. Here, we present an NGS-based bulked-segregant analysis (BSA) technique called Sat-BSA (SVs associated with traits) for identifying SVs controlling traits of interest in crops. Sat-BSA targets allele frequencies at all SNP positions to first identify candidate genomic regions associated with a trait, which is then reconstructed by long reads-based local de novo assembly. Finally, the association between SVs, RNA-seq-based gene expression patterns and trait is evaluated for multiple cultivars to narrow down the candidate genes. We applied Sat-BSA to segregating F₂ progeny obtained from crosses between turnip cultivars with different tuber colors and successfully isolated two genes harboring SVs that are responsible for tuber phenotypes. The current study demonstrates the utility of Sat-BSA for the identification of SVs associated with traits of interest in species with large and heterozygous genomes.     

Pacific Ocean and Japan Sea ecotypes of Japanese beech (Fagus crenata) differ in photosystem responses to continuous high light

Two ecotypes of Japanese beech (Fagus crenata Blume), the Pacific Ocean type (PAO) and the Japan Sea type (JAS), show different responses to high solar irradiance. When PAO and JAS saplings were grown in continuous high-light (H), leaves of JAS became pale green. To elucidate this phenomenon, we investigated in vivo photochemistry based on pigment concentrations of Photosystem (PS) I and PS II and Western blot analysis. In JAS-H leaves, the amount of D1-protein decreased, resulting in decreases in the maximal quantum yield of PS II (F(v)/F(m)) and electron transport rate, whereas PAO-H leaves maintained high activities. The PS I photochemistry determined by measurement of P-700 photo-oxidation showed that the intersystem electron pool size was 1.4 times greater in JAS-H leaves than in PAO-H leaves. Furthermore, the re-reduction kinetics of P-700(+) showed that cyclic electron transport around PS I was 1.2 times faster in PAO-H leaves than in JAS-H leaves. Analysis of the area over the fluorescence induction kinetics indicated that the relative abundance of the PS IIalpha center increased in PAO-H leaves, whereas JAS leaves were observed to have low acclimation capacity to high light. These results demonstrate that PAO leaves possess acclimation mechanisms to continuous high light, whereas JAS leaves are more vulnerable to continuous high light, resulting in reduced leaf longevity owing to photoinhibition caused by increases in the intersystem electron pool size and suppression of photochemistry at the level of PS I and PS II.     

Characteristics of an aminopeptidase from Japanese cedar (Cryptomeria japonica) pollen

A peptidase from Japanese cedar pollen, Jc-peptidase, was clarified to preferentially hydrolyze an MCA substrate of Phe-MCA (L-phenylalanyl-4-methylcoumaryl-7-amide). This study examined substrate specificities of Jc-peptidase using oligopeptides. Jc-peptidase hydrolyzed Phe-Phe and Tyr-Phe effectively and hydrolyzed Leu-Phe, Met-Phe, and Arg-Phe moderately. Other substrates such as Ala-Phe, Asp-Phe, and Pro-Phe were not hydrolyzed with the peptidase. Results obtained with a series of aminoacyl-Phe peptides were compatible with the facts obtained for MCA substrates except for Arg-MCA. Effects of amino acid residues in the P1' position were also examined using Phe-amino acids. An N-terminal phenylalanine residue was actually released from bioactive peptides such as molluscan cardioexcitatory neuropeptide (FMRF-NH(2)). Because the activity was inhibited with Zn(2+) and EDTA, Jc-peptidase was inferred to belong to the metalloproteases. The N-terminal amino acid sequence was determined to be APIGVQLEIEENYVHMYNGF and an internal sequence to be EIFAATFNVDEETEA, but no homology with other proteins was found.     

Immunohistochemical distribution of viral antigens in pigs naturally infected with porcine teschovirus

A distribution of porcine teschovirus (PTV) antigens in pigs naturally infected with PTV is presented using the method of immunohistochemical examination. In the nervous system, PTV antigens were found in the cytoplasm of neuronal cells and glial cells distributed in the spinal ventral horn and brain stem, and also in the cytoplasm of ganglion cells in the spinal ganglion. No antigens were seen in the cerebral hemisphere. In the nervous system, the distribution of PTV antigens was consistent with lesions characteristic of nonsuppurative encephalomyelitis. In the other examined organ, PTV antigens were observed in bronchiolar epithelial cells in the lung, hepatocytes in the liver, epithelial cells in the tonsils and the myenteric nerve plexus in the small and large intestine.     

Complex apocrine carcinoma with dominant myoepithelial proliferation in a dog

A rare case of complex apocrine carcinoma displaying dominant myoepithelial proliferation developed in the right leg subcutis of a 10-year-old male dog. The major cell population consisted of diffusely proliferating p63-expressing neoplastic cells that were largely myoepithelial in origin co-expressing α-smooth muscle actin. A small portion of the cell population consisted of concomitant basal epithelial cells lacking α-smooth muscle actin expression. The minor population consisted of p63-negative apocrine gland cells that expressed cytokeratin 8. The myoepithelial cell population showed a rather stronger proliferation activity than did the apocrine epithelial population. Thus, this tumor might have been derived from basal epithelial cells characterized by more predominant myoepithelial differentiation than luminal apocrine epithelial differentiation.     

Particle Size Effects on the Quality of Flour Tortillas Enriched with Whole Grain Waxy Barley

Wheat tortillas were enriched with whole barley flour (WBF) of different particle sizes including 237 μm (regular [R]), 131 μm (intermediate [IM]), and 68 μm (microground [MG]). Topographical and fluorescent microstructure images of flours, doughs, and tortillas were examined. Flours and tortillas were analyzed for color, protein, ash, starch, moisture, and β‐glucan content. Farinograph testing was conducted on the flour blends. Water activity and texture analyses of tortillas were conducted. A 9‐point hedonic scale was used by 95 untrained panelists to evaluate tortilla appearance, color, flavor, texture, and overall acceptability. Two commercial products (CP) were included in some analyses. As WBF particle size decreased, color was lighter; protein, moisture content and mixing stability decreased; ash, starch content, water absorption and farinograph peak time increased; and β‐glucan content was constant. WBF tortillas were darker than the control (C), while IM and MG tortillas had lower peak forces than C. No flavor differences were reported among C, R, and MG tortillas but higher scores were given to both CP in all attributes tested. Tortillas made with the largest WBF particle size (R) were the most similar in protein content, texture and flavor when compared with C tortillas made with refined bread flour.     

Isolation and genetic analysis of Japanese encephalitis virus from a diseased horse in Japan

Japanese encephalitis (JE) developed in an unvaccinated half-bred horse kept in Tottori Prefecture, Japan. The animal showed ataxia with pyrexia and low appetite, and ultimately died. A viral strain was isolated from the cerebrum of the horse and was identified as JE virus (JEV) by RT-PCR using JEV specific primers. The isolated JEV was classified into genotype I by nucleotide sequence analysis of the viral envelope gene. We believe that this is the first report of the genotype I strain being isolated from a horse.     

Efficient digestion and structural characteristics of cell walls of coffee beans

Screening of effective food-processing cellulase for digestion of cell walls of coffee beans was carried out, and the cellulase from Trichoderma sp. was selected. The digestion of the cell walls of green and roasted coffee beans was carried out by sequential procedures of alkali boiling (0.1 M Na2CO3 buffer, pH 10, and 0.1 M NaOH), cellulase digestion, autoclaving with 0.1 M NaOH, and cellulase redigestion. The total digestion yields were >95 and >96%, respectively. The cell walls became thin, and the final residues of the cell walls were easily broken into small pieces. The neutral sugar analysis of the digestion or the extract and the residues and the microscopy observations with staining with toluidine blue O, Yariv reagent, and calcofluor for the residue in each step were investigated. Four structures, the galactomannan-cellulose (center part), the membrane of the arabinogalactan protein, the cellulose-rich galactomannan layer, and the arabinogalactan protein-rich layers (outer part), were found in the cell walls.     

Regulatory effect of amino acids on the pasting behavior of potato starch is attributable to its binding to the starch chain

The binding of an amino acid, glycine (Gly), alanine (Ala), epsilon-aminocaproic acid (-AC), monosodium glutamate (GluNa), or lysine (Lys), to starch was examined by a biomolecular interaction analyzer (IAsys). A starch sample (ATS) hydrolyzed to an extent of 1% hydrolysis rate with 15% sulfuric acid was used as a model starch for the binding examination. The reducing end of ATS was oxidized by the Somogyi reagent, and the conversion of the reducing end to the carboxyl group of ATS was confirmed by a carboxylic acid fluorescence labeling reagent. The oxidized ATS was immobilized to the amino group of a sensor cuvette by using water-soluble carbodiimide and N-hydroxysuccinimide through an amide bond. The IAsys examination showed that Gly, Ala, and epsilon-AC scarcely bound to the immobilized starch chains but that GluNa and Lys favorably bound with their increasing concentrations. The relative binding index (RBI) of each amino acid was defined by the ratio of the slope of the linear regression equation between the binding response and the concentration for each amino acid to that for Gly. Because the relationships between the RBI and the pasting characteristics (pasting temperature, peak viscosity, breakdown, and swelling index) could each be expressed by a linear regression equation with a high correlation coefficient, it is concluded that the regulation of the pasting behavior of starch with an amino acid is caused by binding of the amino acid to the starch chains.