• Korean Journal of Food Science and Technology
• /
• v.45 no.5
• /
• pp.557-564
• /
• 2013

We isolated and identified antioxidants from acidic and neutral ethyl acetate fractions of the peel of pear (Pyrus pyrifolia N. cv. Chuhwangbae). We isolated 4 compounds from the methanol extract, by using 3 different types of column chromatography (Sephadex LH-20, silica gel, and octadecylsilane) and preparative HPLC. We identified the isolated compounds as (S)-(+)-2-cis-abscisic acid O-${\beta}$-D-glucopyranosyl ester (compound 1), 1-[4-O-${\beta}$-D-glucopyranosyl]phenyl ethanone (picroside, compound 2), ${\beta}$-sitosterol (compound 3), and ${\beta}$-sitosteryl 3-O-${\beta}$-D-glucopyranoside (compound 4) by nuclear magnetic resonance analysis. We are the first to report the identification of compounds 1, 2, and 4 from pear.

• Journal of Life Science
• /
• v.15 no.2 s.69
• /
• pp.298-303
• /
• 2005

This experiment was carried to investigate the optimum time and times of abscisic acid (ABA) treatment for the coloration in 'Kyoho' grapes. The L-phenylalanine ammonia-lyase (PAL) enzyme activities were showed highly in both ABA treatments at veraison and 10 days after veraison. However, PAL enzyme was slightly higher in ABA treatment at 10 days after veraison than in that at veraison. Anthocyanin content showed a tendency that were increased during fruit development after veraison in all treatments, and was the highest in ABA treatment at 10 days after veraison. Fructose and glucose as soluble sugars were detected by HPLC and showed little differences in all treatments. In times of ABA treatment, PAL activity showed a tendency that decreased after increased in all treatments. PAL activity in 2 times treatment of ABA was higher than other treatments. Also, anthocyanin content was highest in 2 times treatment of ABA, as 5 folds of control and folds of 1 time treatment of ABA. Both fructose and glucose contents in all ABA treatments was slightly higher than control.

• Journal of Korean Society of Forest Science
• /
• v.99 no.4
• /
• pp.633-637
• /
• 2010

This study was conducted to evaluate various effects of kinds of culture medium, concentrations of abscisic acid (ABA) or /kinds of osmotica on maturation of somatic embryos (SEs) with four (LL-L, LL-K, LL-P and LL-N) embryogenic tissue lines (ETLs) in Japanese larch (Larix leptolepis). In comparison of two culture medium, the LL-P produced the highest number of the cotyledon-staged SE (134.9/90 mg tissue) in 1/2LM medium. In contrast, no SEs were obtained except the LL-P (32.9) in medium of BLG. Effects of two concentrations of ABA in the medium with four ETL for SEs maturation were also compared. In the test of 60 or 100 ${\mu}M$ ABA, the highest result was obtained in 60 ${\mu}M$ ABA (142.9). However, the influence of ABA had little on SEs production except the LL-N regardless of concentrations of ABA. In comparison of different kinds/concentrations of osmotica, the best response was obtained from the treatment of 0.2 M maltose, the LL-K (540.5). In conclusion, the effects of production of SEs were greatly rely on the ETLs, rather than kinds of medium, concentrations of ABA or osmotica which were used in maturation of SEs.

• Korean Journal of Environmental Biology
• /
• v.23 no.1
• /
• pp.47-51
• /
• 2005

Three-weeks old Commelina communis was transferred to Hoagland solution (Control, 100 μM Cd/sup 2+/, 100 μM Cd/sup 2+/ + 100 μM ABA, 100 μM Cd/sup 2+/+50 mM KCl) and grown for a week in the solution and then a number of physiological activities were investigated. In cases of Cd/sup 2+/ and Cd/sup 2+/ + ABA treatments, the growth of the plants was inhibited to 71 % and 81 %, respectively, when compared with the control, but there were no significant difference of plant growth between Cd/sup 2+/ and Cd/sup 2+/ + KCl- treated plants. In the treatments of Cd/sup 2+/, Cd/sup 2+/ + ABA and Cd/sup 2+/ + KCl total chlorophyll contents were reduced to 32%, 41% and 29%, respectively. In chlorophyll fluorescence experiments, Fv/Fm ratios were also reduced to 14∼20% and about 23%, respectively, according to the light intensity by Cd/sup 2+/ and Cd/sup 2+/+ABA-treated plants. Water stresses were increased by the treatment of Cd/sup 2+/, Cd/sup 2+/ + ABA and Cd/sup 2+/ + KCI. In Cd/sup 2+/ accumulation experiments Cd/sup 2+/ transport into the plant by ABA was not affected, but the accumulation of Cd/sup 2+/ into the roots was elevated to 13% when compared with the control. Cd/sup 2+/ transport into the root was markedly inhibited to 60% by KCl. Therefore, it could be concluded that ABA did not reduce the toxicities of Cd/sup 2+/, but enhanced Cd/sup 2+/ - induced toxicities and KCl showed no effect on Cd/sup 2+/ - induced toxicities.

• Journal of Life Science
• /
• v.34 no.6
• /
• pp.426-433
• /
• 2024

The environmental stress that plants are most susceptible to is water stress. Abscisic acid (ABA) is a plant hormone synthesized by plants to counteract environmental stress. The role of stomata in plants is to allow the synthesis of sucrose by absorbing CO₂, which greatly affects photosynthetic activity. In addition, stomata are pathways for transpiration, which releases H₂O and help establish a water potential gradient that allows plant roots to continuously absorb water and inorganic substances from the soil. Plants have a mechanism to minimize water loss by closing their stomata when exposed to water-stressed environments. The most well-studied hypothesis concerning the mechanism of stomatal closure is the response to water stress. When a plant receives sufficient water, its stomata open during the day and close at night due to its circadian rhythm. In addition, stomatal closure occurs when the concentration of CO₂ in the intercellular space increases. However, the mechanism of stomatal closure due to circadian rhythm and increased CO₂ concentration in the intercellular space is not well understood. When plants undergo water stress, the increased concentration of ABA in the guard cell cytoplasm induces an increase in Ca²⁺ concentration, resulting in cytoplasmic depolarization. As a result, the outward K⁺-channel of the tonoplast and the slow-type anion channels SLAC1 and SLAH3 are activated, releasing K⁺, Cl^-, and malate^2-, causing the stomata to close. Therefore, in this paper, the mechanism of stomatal closure caused by water stress was investigated.

• Journal of Bio-Environment Control
• /
• v.31 no.3
• /
• pp.170-179
• /
• 2022

Glutamic acid is a precursor of essential amino acids that play an important role in plant growth and development. It is one of the biostimulants that reduce cold stress damage by stimulating biosynthetic pathways leading to cryoprotectants. This study evaluated the effects of glutamic acid foliar application on Kimchi cabbage under low-temperature stress. There were six treatments, combining three photo-/dark periods temperature levels (11/-1℃ extremely low, E; 16/4℃ moderately low, M; and 21/9℃ optimal, O) with and without glutamic acid foliar application (0 and 10 mg·L^-1; Glu 0 and Glu 10). Glutamic acid foliar application was sprayed once 10 days after transplanting, and then temperature treatment immediately after glutamic acid foliar application was conducted for up to four days. After four days of treatment, abscisic acid (ABA), phaseic acid (PA), dihydrophaseic acid (DPA), and abscisic acid-glucose ester (ABA-GE) contents were higher with Glu 10 treatment than Glu 0 treatment in M treatment. Glucose content was highest in E with Glu 10 treatment (52.1 mg·100 g^-1 dry weight), while fructose content was highest in O with Glu 0 treatment (134.6 mg·100 g^-1 dry weight). The contents of glucolepiddin (GLP), glucobrassicin (GBS), 4-methoxyglucobrassicin (4MGBS), neoglucobrassicin (GNBS), and gluconasturtiin (GNS) were highest among all treatments in E with Glu 10 treatments (0.72, 2.05, 1.67, 9.40 and 0.85 µmol·g^-1 dry weight). After two days of treatment, rapid changes in PA and DPA contents of E with Glu 10 treatments were confirmed, and several individual glucosinolate contents (GLP, GBS, 4MGBS, GNBS, and GNS) were significantly different depending on low temperature and glutamic acid treatment. In addition, the content of fructose was significantly lower than that of O treatment in E and M treatments after four days of treatment. Therefore, although the changes in PA, DPA, glucose, fructose, and individual glucosinolates according to low temperature and glutamic acid foliar treatment were shown. A clear correlation between low temperature and glutamic acid effects could not be evaluated. Results indicated that Brassica crops are cryophilic vegetables, do not react sensitively to low temperatures, and mostly have cold resistance.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.10a
• /
• pp.92-92
• /
• 2017

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2018.04a
• /
• pp.179-179
• /
• 2018

• Bulletin of the Korean Chemical Society
• /
• v.30 no.6
• /
• pp.1376-1378
• /
• 2009

• Journal of Plant Biology
• /
• v.32 no.4
• /
• pp.255-264
• /
• 1989

Ginseng zygotic embryos, seedlings, and exised cotyledonary nodes were cultured on Murashinge and Skoog's(MS) medium, supplemented with 6-benzyladenine(BA) and gibberellic acid(GA3) to induce flower buds. As the concenteration of nitrogen compounds in MS medium was reduced to half of its strength, the flowering frequency of zygotic embryos increased up to 90%. The optimum concentration of sucrose in the medium for flowering of seedlings was 30-60 g/1. In all cases flower buds were formed on elongated axillary branches from the cotyledonary nodes, while the apices remained vegetative. When zygotic embryos and excised cotyledonary nodes were cultured on the medium, supplemented with all possible combinations of BA, GA3, and abscisic acid(ABA) of 5 $\mu$M indole-3-acetic acid(IAA) in the above combinations did not affect flowering. These results suggest that cytokinins, gibberellins, and inhibitors play primary, permissive, and preventive roles, respectively, in the induction of flowering of ginseng.