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181 results on '"Ohsugi, Ryu"'

9. Simultaneous analysis of amino acids and carboxylic acids by capillary electrophoresis--mass spectrometry using an acidic electrolyte and uncoated fused-silica capillary

Author

Wakayarna, Masataka, Aoki, Naohiro, Sasaki, Haruto, and Ohsugi, Ryu

Subjects
Mass spectrometry -- Methods, Electrolytes -- Usage, Amino acids -- Chemical properties, Carboxylic acids -- Chemical properties, Electrophoresis -- Methods, Chemistry
Abstract

A simple, low-cost capillary electrophoresis--mass spectrometry (CE-MS) method is demonstrated for the simultaneous analysis of amino acids and small carboxylic acids (glycerate, lactate, fumarate, succinate, malate, tartrate, citrate, iso-citrate, cis-aconitate, and shikimate). All CE-MS experiments were performed using a single uncoated fused-silica capillary and with a single separation electrolyte, formic acid. For CE polarity, the CE inlet was set as the anode, and the MS side was set as the cathode. By using high-speed sheath gas flow, the apparent mobilities of all compounds were sped up; thus, the migration times of the carboxylic acids were reduced. In positive ion mode ESI-MS detection, small carboxylic acids were detected faintly as m/z = [[M + 18].sup.+] or [[M + 23].sup.+], after protonated molecule detection (m/z = [[M + 1].sup.+]) of the amino acids. In negative ion mode, all of these small carboxylic acids were detected clearly as deprotonated molecules (m/z = [[M - 1].sup.-]), after detection of the amino acids. By changing the polarity of the MS during CE separation, both amino acids and small carboxylic acids were detectable in a single electrophoresis analysis run. With this method, the diurnal metabolic changes of pineapple leaves were observed as reflecting Crassulacean acid metabolism. 10.1021/ac1019039

Published
2010

15. Additional file 1: Table S1. of Genetic Evidence for the Role of a Rice Vacuolar Invertase as a Molecular Sink Strength Determinant

Author

Shamitha Morey, Tatsuro Hirose, Hashida, Yoichi, Miyao, Akio, Hirochika, Hirohiko, Ohsugi, Ryu, Yamagishi, Junko, and Aoki, Naohiro

Subjects
food and beverages
Abstract

Details of primers used in this study. Figure S1. Confirmation of the presence of aberrant transcripts in the mutants (KO) using semi-quantitative PCR. Figure S2. Expression in the spikelet using promoter: GUS lines. Figure S3. Number of rachis branches and grain size differences between the field-grown WT and the mutants (KO). Figure S4. Photosynthesis rates for the WT and mutants (KO) at various growth stages from panicle initiation to late ripening. Figure S5. VIN, NIN and CWIN activity, and mRNA abundance of OsINV2 in young panicles (~â 4â 5Â cm in length) at panicle initiation for WT and the mutants (KO). (PPTX 59980 kb)

Published
2018
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23. High Temperature During Rice Grain Filling Enhances Aspartate Metabolism in Grains and Results in Accumulation of Aspartate-Family Amino Acids and Protein Components

Author

Yan Wang, Guang-li Xu, Cheng-gang Liang, Qing Zhang, Ohsugi Ryu, and Li Tian

Subjects
chemistry.chemical_classification, Methionine, biology, Lysine, food and beverages, Plant Science, Metabolism, lcsh:Plant culture, Amino acid, high temperature, chemistry.chemical_compound, chemistry, Biochemistry, aspartate aminotransferase, Glutelin, biology.protein, lcsh:SB1-1110, Threonine, Isoleucine, Prolamin, Agronomy and Crop Science, aspartokinase, Biotechnology, aspartate-family amino acid, protein component
Abstract

Global warming causes the exacerbation of rice growing environment, which seriously affects rice growth and reproduction, and finally results in the decrease of rice yield and quality. We investigated the activities of aspartate metabolism enzymes in grains, and the contents of Aspartate-family amino acids and protein components to further understand the effects of high temperature (HT) on rice nutritional quality during rice grain filling. Under HT, the average activities of aspartate aminotransferase (AAT) and aspartokinase (AK) in grains significantly increased, the amino acid contents of aspartate (Asp), lysine (Lys), threonine (Thr), methionine (Met) and isoleucine (Ile) and the protein contents of albumin, globulin, prolamin and glutelin also significantly increased. The results indicated that HT enhanced Asp metabolism during rice grain filling and the enhancement of Asp metabolism might play an important role in the increase of Asp-family amino acids and protein components in grains. In case of the partial appraisal of the change of Asp-family amino acids and protein components under HT, we introduced eight indicators (amino acid or protein content, ratio of amino acid or protein, amino acid or protein content per grain and amino acid or protein content per panicle) to estimate the effects of HT. It is suggested that HT during rice grain filling was benefit for the accumulation of Asp-family amino acids and protein components. Combined with the improvement of Asp-family amino acid ratio in grains under HT, it is suggested that HT during grain filling may improve the rice nutritional quality. However, the yields of parts of Asp-family amino acids and protein components were decreased under HT during rice grain filling.

Published
2013

35. Mutation of the SP1 gene is responsible for the small-panicle trait in the rice cultivar Tachisuzuka, but not necessarily for high sugar content in the stem.

Author

Hirose, Tatsuro, Kadoya, Sakurako, Hashida, Yoichi, Okamura, Masaki, Ohsugi, Ryu, and Aoki, Naohiro

Subjects
RICE varieties, PLANT mutation, CROP growth, EFFECT of sugars on plants, PLANT stems
Abstract

Tachisuzuka, a rice cultivar grown for whole-crop silage, is characterized by the small-panicle trait and high-stem sugar content. To investigate the interrelationship between the two features, we attempted to identify the gene responsible for the small-panicle trait in Tachisuzuka, and also to examine the function of the gene using a knockout mutant line. A functionally disruptive deletion of the nucleotide sequence was found in the geneSP1(Short-Panicle 1; Os11g0235200) in Tachisuzuka, which has been reported as a candidate gene for the small-panicle trait. A gene knockout mutant ofSP1obtained from the cultivar Nipponbare showed a small-panicle phenotype similar to that observed in Tachisuzuka. However, soluble sugar content in the stem did not increase in the knockout line, whereas starch content increased significantly. Overall, disruption ofSP1is responsible for the small-panicle phenotype of Tachisuzuka, but it is only partially associated with the high-stem sugar content. [ABSTRACT FROM PUBLISHER]

Published
2017
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36. Suppression of starch accumulation in ‘sugar leaves’ of rice affects plant productivity under field conditions.

Author

Okamura, Masaki, Hirose, Tatsuro, Hashida, Yoichi, Ohsugi, Ryu, and Aoki, Naohiro

Subjects
RICE starch, CROP growth, LEAVES, PLANT productivity, BIOACCUMULATION in plants, SUCROSE
Abstract

While many plants accumulate the majority of their photoassmilates as starch during the daytime, some plants accumulate sucrose. Although the existence of these high-sucrose leaves, called ‘sugar leaves’, has long been known, the physiological characteristics of sugar leaves compared to ‘starch leaves’ remain unclear. In this study, the physiological roles of starch accumulation in rice, which has typical sugar leaves, were investigated using a mutant with suppressed leaf-starch biosynthesis. When grown under controlled conditions with light intensity of 400 μmol m−2s−1, the initial growth of the mutant was similar to that of the wild-type plant, even with a 6-h-light/18-h-dark photoperiod in which carbon resources for growth are required during the night. This finding indicates that rice does not rely on leaf starch as a carbon resource during the night. By contrast, under field conditions, the grain yields of the mutant were significantly lower than those of the wild type only when the plants were exposed to full sunlight during the ripening period. These results may indicate that starch accumulation in sugar leaves plays an important role in maintaining a high source capacity under sufficient light conditions rather than as a carbon resource for the plant’s growth at night. [ABSTRACT FROM PUBLISHER]

Published
2017
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38. Evaluation of performance of sorghum varieties grown in Tokyo for sugar accumulation and its correlation with vacuolar invertase genes SbInv1and SbInv2

Author

Morey, Shamitha Rao, Hashida, Yoichi, Ohsugi, Ryu, Yamagishi, Junko, and Aoki, Naohiro

Abstract

ABSTRACTThe sugar-accumulating potential of global and local sweet and grain sorghum varieties were tested under the local conditions. The basis for this study was the dependency of sugar accumulation on temperature and photoperiod. Thus, the efficacy of cultivars as a bioenergy source would need to be determined based on their performance under the local environmental conditions. A strong correlation of sucrose content with brix was observed, enabling large-scale screening of varieties for high sucrose content. The morphological characteristics inherent in sweet sorghum, such as tall stems, greater number of leaves and a longer vegetative period, were found to correlate with the total stem sugar content. Assessment of sugars along the stem revealed maximum sugar accumulation in the upper intermediate to upper internodes in most of the varieties tested. The maximum theoretical ethanol yield (MTEY), a function of brix and juice yield, was determined as a better indicator of testing the performance of a variety as a potential source of bioethanol, mainly due to a negative correlation of stem juiciness and sucrose content in the varieties tested. Further, the relative expression of vacuolar invertase genes, SbINV1and SbINV2, was studied, and a strong negative correlation of SbINV2to stem sucrose content was observed. This reveals a possibility of involvement of vacuolar invertase gene, SbINV2, in sugar accumulation in sweet sorghum stems, and as a key candidate for molecular breeding studies for higher stem sugar content.

Published
2018
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45. Mutation of the SP1gene is responsible for the small-panicle trait in the rice cultivar Tachisuzuka, but not necessarily for high sugar content in the stem

Author

Hirose, Tatsuro, Kadoya, Sakurako, Hashida, Yoichi, Okamura, Masaki, Ohsugi, Ryu, and Aoki, Naohiro

Abstract

AbstractTachisuzuka, a rice cultivar grown for whole-crop silage, is characterized by the small-panicle trait and high-stem sugar content. To investigate the interrelationship between the two features, we attempted to identify the gene responsible for the small-panicle trait in Tachisuzuka, and also to examine the function of the gene using a knockout mutant line. A functionally disruptive deletion of the nucleotide sequence was found in the gene SP1(Short-Panicle 1; Os11g0235200) in Tachisuzuka, which has been reported as a candidate gene for the small-panicle trait. A gene knockout mutant of SP1obtained from the cultivar Nipponbare showed a small-panicle phenotype similar to that observed in Tachisuzuka. However, soluble sugar content in the stem did not increase in the knockout line, whereas starch content increased significantly. Overall, disruption of SP1is responsible for the small-panicle phenotype of Tachisuzuka, but it is only partially associated with the high-stem sugar content.

Published
2017
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