The effect of water stress induced to enhance sugar accumulation in Satsuma mandarin (Citrus unshiu Marc.) fruit was investigated. Satsuma mandarin trees were subjected to water stress using mulch cultivation from late August to early... more
The effect of water stress induced to enhance sugar accumulation in Satsuma mandarin (Citrus unshiu Marc.) fruit was investigated. Satsuma mandarin trees were subjected to water stress using mulch cultivation from late August to early December. In mulch treatment, soil was covered with double-layered plastic sheets that prevented rainfall from permeating the soil, but allowed water from soil to evaporate. The water status of soil, fine roots, pericarps, and juice vesicles was determined using the isopiestic psychrometer. As the severity of water stress increased, both water potential and osmotic potential of fine roots and pericarps significantly decreased in plants grown under mulch cultivation compared to well-watered trees. Although water potential and osmotic potential decreased, turgor of both roots and pericarps of the water stressed trees did not decrease under water stress conditions. Because turgor was maintained, osmoregulation occurred in Satsuma mandarin trees in respons...
Research Interests:
Research Interests:
Cell enlargement depends on a growth-induced difference in water potential to move water into the cells. Water deficits decrease this potential difference and inhibit growth. To investigate whether the decrease causes the growth... more
Cell enlargement depends on a growth-induced difference in water potential to move water into the cells. Water deficits decrease this potential difference and inhibit growth. To investigate whether the decrease causes the growth inhibition, pressure was applied to the roots of soybean (Glycine max L. Merr.) seedlings and the growth and potential difference were monitored in the stems. In water-limited plants, the inhibited stem growth increased when the roots were pressurized and it reverted to the previous rate when the pressure was released. The pressure around the roots was perceived as an increased turgor in the stem in small cells next to the xylem, but not in outlying cortical cells. This local effect implied that water transport was impeded by the small cells. The diffusivity for water was much less in the small cells than in the outlying cells. The small cells thus were a barrier that caused the growth-induced potential difference to be large during rapid growth, but to reve...
Research Interests:
Research Interests:
We report the combination of a piezoelectric inkjet and a surface modified sharp tipped probe for the direct sampling and rapid mass spectrometric analysis of metabolites in plant single cells.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
This experiment was carried out to study the growth mechanisms of tomato fruits in relation to water uptake and enlargement of cells in fruit pericarp. Growth parameters of tomato fruit such as cell layers, cell diameter and thickness of... more
This experiment was carried out to study the growth mechanisms of tomato fruits in relation to water uptake and enlargement of cells in fruit pericarp. Growth parameters of tomato fruit such as cell layers, cell diameter and thickness of fruit pericarp, functional xylem vessels ...
Research Interests:
Research Interests:
Two cultivars of tulip (Tulipa gesneriana L.) were used to check the effect of trehalose-feeding on longevity of vase life. `Oxford' plants were grown from bulbs, and trehalose-fed cut flowers were compared with the intact plants... more
Two cultivars of tulip (Tulipa gesneriana L.) were used to check the effect of trehalose-feeding on longevity of vase life. `Oxford' plants were grown from bulbs, and trehalose-fed cut flowers were compared with the intact plants grown in pots. `Pink Diamond' flowers were obtained commercially as cut flowers from the market, and trehalose-feeding was examined by using only flower parts. In both cultivars of plants, it was confirmed that trehalose-feeding enhanced longevity of the vase life significantly at room temperature. Additionally, mechanisms of prolonging the vase life with trehalose-fed flowers were studied by comparing the water status in the zone of elongation of tulip tepals when their growth rates were modified with different treatments. In the elongating region of tulip tepals, cell elongation rates were linearly correlated to sizes of the growth-induced water potential regardless of treatments. It was found that trehalose-feeding reduced the hydraulic conductan...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Chemistry and Germination
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Materials Science, Chemistry, Analytical Chemistry, Chromatography, Mass Spectrometry, and 15 morePhospholipids, Medicine, Humans, Mice, Animals, Renal cell Carcinoma, Glyphosate, Derivatization, Molecular Diagnostic Techniques, Furans, Alcohols, Solvents, Glufosinate, Electrospray Ionization, and Pharmacology and pharmaceutical sciences
Research Interests:
Research Interests:
Research Interests:
Foehn-like extreme hot and dry wind conditions (34°C, >2.5 kPa vapor pressure deficit, and 7 m s(-1)) strongly affect grain quality in rice (Oryza sativa L.). This is a current concern because of the increasing frequency and intensity... more
Foehn-like extreme hot and dry wind conditions (34°C, >2.5 kPa vapor pressure deficit, and 7 m s(-1)) strongly affect grain quality in rice (Oryza sativa L.). This is a current concern because of the increasing frequency and intensity of combined heat and water-deficit stress under climate change. Foehn-induced dry wind conditions during the grain-filling stage increase ring-shaped chalkiness as a result of spatiotemporal reduction in starch accumulation in the endosperm, but kernel growth is sometimes maintained by osmotic adjustment. Here, we assess the effects of dry wind on chalky ring formation in environmentally controlled growth chambers. Our results showed that hot and dry wind conditions that lasted for >24 h dramatically increased chalky ring formation. Hot and dry wind conditions temporarily reduced panicle water potential to -0.65 MPa; however, kernel growth was maintained by osmotic adjustment at control levels with increased transport of assimilate to the growing...
Research Interests:
Research Interests: Chemistry, Analytical Chemistry, Mass Spectrometry, Calcium, Medicine, and 11 moreElectrospray, Fructans, Magnesium, Chelating agent, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Enseñanza - Aprendizaje Ciencias Naturales Y Exactas, Ethylenediaminetetraacetic Acid (EDTA), Edetic Acid, Electrospray Ionization, Maltose, and Ciencias Químicas
Research Interests:
Research Interests:
Research Interests:
Detergents are necessarily used for different extraction protocols of proteins from biological cells or tissues. After the extraction, elimination of detergent is necessary for the better performance of electrospray ionization mass... more
Detergents are necessarily used for different extraction protocols of proteins from biological cells or tissues. After the extraction, elimination of detergent is necessary for the better performance of electrospray ionization mass spectrometry (ESI-MS). Elimination of detergents is laborious and time-consuming, and also sample loss may be unavoidable. Probe electrospray ionization (PESI) developed in our laboratory has been found to be tolerant to the presence of salts and buffers in sample solutions. In this report, it was examined whether PESI is applicable to the sample solutions that contain high-concentration of detergents. It was found that PESI is highly tolerant to the presence of sodium dodecyl sulphate, cetyl trimethylamminium bromide, Triton X100 and 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate compared with conventional ESI and nanoESI. Therefore, PESI can be a potential analytical tool for direct analysis of protein extracts and digests containing high-concentration detergents.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
In an effort to gain an understanding of the processes governing ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI), direct comparison was made of the mass spectra of proteins, carbohydrates and synthetic polymers... more
In an effort to gain an understanding of the processes governing ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI), direct comparison was made of the mass spectra of proteins, carbohydrates and synthetic polymers (polyethylene glycol, polyester and polyamide) by using pyridylindoles, pyridoindoles and pyridylpyridoindoles as UV (337 nm)-MALDI-TOFMS matrices in positive and negative ion mode. In order to study the combined effect of the indole N-H and the pyridine nitrogen of the MALDI matrix on the desorption/ionization process in MALDI, compounds were selected that include either or both of these functions in their structure. Within the compounds studied only those that possess simultaneously both functions in a 1,4-relation behave as very good matrices for proteins. These compounds also work as matrices for some carbohydrates and synthetic polymers used as analytes in the present study. Some of the compounds were also found to be useful for the post-source decay (PSD) analysis of cyclodextrins in positive and negative ion mode. In several cases we also examined the matrix behavior of the corresponding N-methylindole derivatives.
Research Interests:
Research Interests:
The in vitro protein import experiment is one of the most important techniques for determining protein localization. For chloroplastic proteins, proteins of interest are incubated with isolated chloroplasts in the presence of energy... more
The in vitro protein import experiment is one of the most important techniques for determining protein localization. For chloroplastic proteins, proteins of interest are incubated with isolated chloroplasts in the presence of energy sources. Radio-labeled proteins synthesized either in vitro or in vivo have been widely used as substrate proteins. Here we report our development of the protein import assay system in which non-radio-labeled proteins, overexpressed in Escherichia coli, were applied. In this system, substrate proteins were designed to carry epitope-tags, thus allowing analysis of imported proteins by SDS-PAGE, followed by immunoblotting to detect these tags. Furthermore, the imported proteins were found to be incorporated into their native form. These observations indicated that recombinant proteins were imported into chloroplasts and folded correctly. Therefore, this assay system could represent another valuable tool for determining protein localization.