Nami Goto-Yamamoto
Hiroshima University
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Publication
Featured researches published by Nami Goto-Yamamoto.
Functional & Integrative Genomics | 2010
Kazuya Koyama; Keiko Sadamatsu; Nami Goto-Yamamoto
We investigated the effect of exogenous abscisic acid (ABA) application on the transcriptome as well as the phenolic profiles in the skins of Vitis vinifera cv. Cabernet Sauvignon grape berries grown on the vine and cultured in vitro. ABA application rapidly induced the accumulation of anthocyanin and flavonol. Correlatively, the structural genes in the phenylpropanoid and flavonoid pathways, their transcriptional regulators, as well as genes considered to be involved in the acylation and transport of anthocyanin into the vacuole, were upregulated by ABA treatment. The Genechip analysis showed that the ABA treatment significantly up- or downregulated a total of 345 and 1,482 transcripts in the skins of berries grown on the vine and cultured in vitro, respectively. Exogenous ABA modulated the transcripts associated with osmotic responses, stress responses, cell wall modification, auxin and ethylene metabolism and responses, in addition to the induction of anthocyanin biosynthetic genes, and reduced those associated with photosynthesis; approximately half of these transcripts were identical to the previously reported ripening-specific genes.
Phytochemistry | 2012
Kazuya Koyama; Hiroko Ikeda; Puspa Raj Poudel; Nami Goto-Yamamoto
Biosynthesis of phenolic compounds is known to be sensitive to light environments, which reflects the possible role of these compounds for photoprotection in plants. Herein, the effects of UV and visible light on biosynthesis of flavonoids was investigated, i.e., proanthocyanidins (PAs) and flavonols, in young berry skins of a red-wine grape, Vitis vinifera cv. Cabernet Sauvignon. Shading with light-proof boxes from the flowering stage until 49 days after treatment (DAT) partially decreased PA concentrations, and completely decreased flavonol concentrations in the berry skins. Shading decreased the transcript abundance of a flavonol-related gene more remarkably than those of PA-related genes. In addition, light exclusion influenced the composition of PAs, such as the decrease in the proportion of trihydroxylated subunits and the mean degree of polymerization (mDP) within PAs. However, solar UV exclusion did not affect the concentration and composition of PAs, whereas this exclusion remarkably decreased the flavonol concentration. Consistently, UV exclusion did not influence the transcript levels of PA-related genes, whereas it dramatically decreased that of flavonol-related genes. These findings indicated a different light regulation of the biosynthesis of these flavonoids in young berry skins of wine grape. Visible light primarily induces biosynthesis of PAs and affects their composition, whereas UV light specifically induces biosynthesis of flavonols. Distinct roles of members of a MYB transcription factor family for light regulation of flavonoid biosynthesis were proposed.
Yeast | 2001
Masatoshi Azumi; Nami Goto-Yamamoto
Using nine primer pairs, amplified fragment length polymorphism (AFLP) analysis was conducted to characterize industrial, laboratory and type strains of Saccharomyces sensu stricto. S. cerevisiae, S. bayanus, S. carlsbergensis and S. paradoxus had species‐specific AFLP profiles, with some variations among the strains. Nineteen wine, ale, bakery, whisky and laboratory strains of S. cerevisiae were differentiated by two primer pairs, while out of 19 strains of sake yeast, two groups consisting of two and eight strains were not differentiated using nine primer pairs. A phenogram of 41 strains of S. cerevisiae, two strains of S. bayanus, the type strain of S. pastorianus, three strains of S. carlsbergensis, one hybrid strain of S. cerevisiae and S. bayanus and the type strain of S. paradoxus was obtained by the unweighted pair group method, using arithmetic averages (UPGMA) based on the percentage of shared AFLP fragments of each sample pair. This phenogram demonstrated clear separations of S. cerevisiae, S. bayanus, S. carlsbergensis and S. paradoxus. However, S. pastorianus ATCC 12752T showed the highest percentages of shared fragments with the strains of S. bayanus, and formed a cluster with them. Except for the type strain of S. pastorianus, the percentages of shared fragments showed a similar tendency with reported data of DNA relatedness. The cluster of S. cerevisiae separated into three subclusters: one consisting of sake and shochu strains and a whisky strain; another consisting of bakery, wine, ale and whisky strains; and a third consisting of laboratory strains. Copyright
Plant Science | 2002
Nami Goto-Yamamoto; G.H. Wan; K. Masaki; S. Kobayashi
Abstract Chalcone synthase catalyzes the first step for the biosynthesis of anthocyanin, which is an important component of grapevine for red wine making. To reveal the details of the gene family of the chalcone synthase of grapevine, three genomic clones of the chalcone synthase gene, Chs1 (AB015872), Chs2 (AB066275), and Chs3 (AB066274), were obtained from Vitis vinifera cv. Cabernet Sauvignon, and their structure and mRNA accumulation in grape berry skin and other tissues were compared. The homology between Chs1 and Chs2 (96% on the amino acid level) was higher than the homologies between Chs3 and Chs1 and Chs3 and Chs2 (89% each). Phylogenetic analysis showed that Chs3 was more closely related to morning glory Chs-E and petunia Chs-A than to Chs1 and Chs2. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that the mRNA of Chs3 accumulated mainly in the berry skin of red cultivars during coloration, while the mRNA of Chs1 and Chs2 accumulated in the leaves and berry skin of a white cultivar as well as red cultivars. Thus, the three Chss of grapevine seemed to be under a different transcription control.
Bioscience, Biotechnology, and Biochemistry | 2006
Akiko Fujita; Nami Goto-Yamamoto; Isao Aramaki; Katsumi Hashizume
In order to investigate the control mechanism of flavonol biosynthesis of grapevine, we obtained five genomic sequences (FLS1 to FLS5) of putative flavonol synthase genes from Vitis vinifera cv. Cabernet Sauvignon. The mRNA of five FLSs accumulated in flower buds and flowers, while the mRNA of FLS2, FLS4, and FLS5 accumulated in small berry skins and then decreased toward veraison. At the ripening stage, the mRNA of only FLS4 and FLS5 accumulated again. This change in mRNA accumulation did not contradict the flavonol accumulation in the berry skins. Shading of the berries completely inhibited the increase in flavonol content and mRNA accumulation of FLS4, but did not affect the mRNA accumulation of FLS5. The effects of light and plant hormones on flavonol accumulation were different from those on anthocyanin accumulation. Thus flavonol biosynthesis appears to be under a different control system from that of anthocyanin biosynthesis.
Bioscience, Biotechnology, and Biochemistry | 2006
Hiroshi Yakushiji; Shozo Kobayashi; Nami Goto-Yamamoto; Soek Tae Jeong; Tamotsu Sueta; Akifumi Azuma
A white-wine grape, Pinot Blanc, is thought to be a white-skinned mutant of a red-wine grape, Pinot Noir. Pinot Noir was heterozygous for VvmybA1. One allele was the non-functional VvmybA1a, and the other was the functional VvmybA1c. In Pinot Blanc, however, only VvmybA1a was observed, and the amount of VvmybA1 DNA in Pinot Blanc was half that in Pinot Noir. These findings suggest that deletion of VvmybA1c from Pinot Noir resulted in Pinot Blanc.
Bioscience, Biotechnology, and Biochemistry | 2007
Kazuya Koyama; Nami Goto-Yamamoto; Katsumi Hashizume
The extraction of phenolics from berry skins and seeds of the grape, Vitis vinifera cv. Cabernet Sauvignon, during red wine maceration and the influence of different temperature conditions (cold soak and/or heating at the end of maceration) were examined. Phenolics contained mainly in berry skins, viz., anthocyanin, flavonol, and epigallocatechin units within proanthocyanidins, were extracted during the early stage of maceration, whereas those in seeds, viz., gallic acid, flavan-3-ol monomers, and epicatechin-gallate units within proanthocyanidins, were gradually extracted. In addition to their localization, the molecular size and composition of the proanthocyanidins possibly influenced the kinetics of their extraction. Cold soak reduced the extraction of phenolics from the seeds. Heating at the end of maceration decreased the concentration of proanthocyanidins. Thus, modification of the temperature condition during maceration affected the progress of the concentration of phenolics, resulting in an alteration of their make-up in the finished wine.
Journal of Bioscience and Bioengineering | 2000
Seiji Akamatsu; Hisaya Kamiya; Nobuo Yamashita; Toru Motoyoshi; Nami Goto-Yamamoto; Takeaki Ishikawa; Naoto Okazaki; Akira Nishimura
To reveal the mechanism of the production of acetate by sake yeast (Saccharomyces cerevisiae), the expression of genes encoding aldehyde dehydrogenase (ALD), acetyl-CoA synthetase (ACS) and acetyl-CoA hydrolase (ACH), which are related to acetate production, was investigated. Northern blot analysis using total RNA of sake yeast isolated from sake mash revealed that all of the tested genes, ACS1, ACS2, ALD2/3, ALD4, ALD6 and ACH1, were transcribed during sake fermentation. Transcription of ALD2/3 was detected only in the early stage of sake fermentation. A static culture of sake yeast in hyperosmotic media including 1 M sorbitol or 20% glucose resulted in high acetate production and increased transcription of ALD2/3. This is the same result as reported in an aerobic condition, and induction of ALD2/3 seemed to be one reason for high acetate production at high glucose concentration during fermentation. Overexpression of ACS2 resulted in low acetate production both during small-scale sake fermentation and in a static liquid culture. On the other hand, over-expression of ACS1 did not change acetate productivity significantly in a static culture. These results indicate that ALD2/3 and ACS2 play important roles for acetate production during sake fermentation.
Journal of Chromatography A | 2011
Kei Takahashi; Nami Goto-Yamamoto
Free medium-chain fatty acids (MCFAs) can negatively influence the fermentation process and taste quality in alcoholic beverages. Ethyl hexanoate is important in providing a fruit-like flavour to drinks, particularly in Japanese sake. In this study, we developed a direct injection method for a gas chromatography-flame ionization detector following the semi-purification of chemical components, such as esters, alcohols and MCFAs in alcoholic beverages. Evaluation of MCFAs by this method gave a limit of detection on the order of sub-ppm and relative standard deviations less than 10% in standard solution. Good repeatability and recovery rates against MCFAs and ethyl hexanoate were also obtained in non-distilled real alcoholic beverages. Because this method enabled us to simultaneously quantify the concentrations of MCFAs and ethyl hexanoate, the proportion of ester against MCFAs was proposed as a quality control index. This method could be suitable for routine analysis in the alcohol beverage industry.
Journal of Bioscience and Bioengineering | 2011
Yukiko Maeda; Masaki Okuda; Katsumi Hashizume; Midori Joyo; Shigeaki Mikami; Nami Goto-Yamamoto
Some oligopeptides and amino acids have a strong influence on the sensory qualities of sake, but the formation process of such compounds in sake mash has not been well elucidated. In this study, we investigated the formation process of bitter-tasting peptides derived from rice proteins in sake mash, because knowledge about their formation may contribute to the quality control of sake. We analyzed rice protein hydrolysates in sake mash, as well as in the enzymatic digest of steamed rice grains digested by either sake-koji or by crude enzyme extracted from sake-koji. SDS-PAGE showed that a smaller amount of polypeptides (>M.W. 10,000) accumulated in the supernatant of sake mash than in either enzymatic digest. The concentration of peptides in the supernatant of sake mash increased gradually from the early stages of fermentation. Five bitter-tasting peptides (No. 9, <QLFNPS; No. 13, <QLFNPSTNP; No. 17, <QLFNPSTNPWH; No. 18, <QLFNPSTNPWHSP; No. 20, <QLFGPNVNPWHNP), which were previously found in sake mash, were not found in significant amounts in sake-koji. On the other hand, these peptides accumulated at the early stages of both sake mash fermentation and the enzymatic digests, although the levels in sake mash were higher than those in the digests. The present study demonstrated that the 5 bitter-tasting peptides formed in high concentrations when steamed rice grains were digested under conditions of sake mash fermentation with yeast.