• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.609-615
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• 2011

Forsythia saxatilis is a Korean endemic plant designated as rare and endangered by the Korea Forest Service (KFS). Growth and physiological characteristics of F. saxatilis were investigated under two different light intensities in order to figure out an appropriate growth environment for conservation and restoration of the species in its natural habitat. Shoot length, leaf size and weight, photosynthetic pigment content and photosynthetic parameters were measured for F. saxatilis grown at two experimental plots under relative light intensities (RLI) of 20% and 60% of the full sun, respectively. Fresh leaf weight of plants grown under high relative light intensities (RLI-60) exceeded that of plants grown at 20% RLI. The ratio of fresh leaf weight to leaf size at RLI-60 was 1.47 times superior comparing to that recorded at RLI-20. The content of photosynthetic pigments such as chlorophyll a, b and carotenoid were higher in plants grown at RLI-60, whereas the ratio of total chlorophyll to carotenoid content was higher in the leaves at RLI-20. Photosynthetic rate, stomatal conductance and transpiration rate at RLI-60 were, respectively, 2.5, 2.65 and 1.79 times higher comparing to those recorded at RLI-20. Water use efficiency, however, was higher at RLI-20. The chlorophyll/nitrogen ratio was 1.83 times higher at RLI-20 than at RLI-60. In contrast, the ratio of net photosynthesis to chlorophyll content at RLI-60 was 2.58 times higher than that of RLI-20. In conclusion, light intensity might be the major factor affecting growth and physiological characteristics of F. saxatilis grown under canopy of tall tree species.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.88-96
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• 2024

This study was conducted to determine the optimal light conditions for the in situ and ex situ conservation and restoration of Osmanthus insularis, a rare plant species in South Korea. Evaluations included the growth performance, leaf morphological features, photosynthetic characteristics, and photosynthetic pigment contents of seedlings grown from April to November under different light conditions (100%, 55%, 20%, and 10% relative light intensity). The shoot lengths and root collar diameters did not differ significantly with relative light intensity. The dry weights of leaves, stems, and roots and the leaf number were highest at 55% relative light intensity. The leaf shape showed morphological acclimation to light intensity, with leaf area decreasing and thickness increasing as the relative light intensity increased. Several leaf parameters, including photosynthetic rate and stomatal conductance at light saturation point, net apparent quantum yield, and dark respiration, as well as chlorophyll a, chlorophyll b, and carotenoid contents, were all highest at 55% relative light intensity. Under full light conditions, the leaves were the smallest and thickest, but the chlorophyll content was lower than at 55% relative light intensity, resulting in lower photosynthetic ability. Plants grown at 10% and 20% relative light intensity showed lower chlorophyll a, chlorophyll b, and carotenoid contents, as well as decreased photosynthetic and dark respiration rates. In conclusion, O. insularis seedlings exhibited morphological adaptations in response to light intensity; however, no physiological responses indicating enhanced photosynthetic efficiency in shade were evident. The most favorable light condition for vigorous photosynthesis and maximum biomass production in O. insularis seedlings appeared to be 55% relative light intensity. Therefore, shading to approximately 55% of full light is suggested for the growth of O. insularis seedlings.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.265-275
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• 2002

Flavonoid biosynthesis is one of the most extensively studied areas in the secondary metabolism. Due to the study of flavonoid metabolism in diverse plant system, the pathways become the best characterized secondary metabolites and can be excellent targets for metabolic engineering. These flavonoid-derived secondary metabolites have been considerably divergent functional roles: floral pigment, anticancer, antiviral, antitoxin, and hepatoprotective. Three species have been significant for elucidating the flavonoid metabolism and isolating the genes controlling the flavonoid genes: maize (Zea mays), snapdragon (Antirrhinum majus) and petunia (Prtunia hybrida). Recently, many genes involved in biosynthesis of flavonoid have been isolated and characterized using mutation and recombinant DNA technologies including transposon tagging and T-DNA tagging which are novel approaches for the discovery of uncharacterized genes. Metabolic engineering of flavonoid biosynthesis was approached by sense or antisense manipulation of the genes related with flavonoid pathway, or by modified expression of regulatory genes. So, the use of a variety of experimental tools and metabolic engineering facilitated the characterization of the flavonoid metabolism. Here we review recent progresses in flavonoid metabolism: confirmation of genes, metabolic engineering, and applications in the industrial use.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.2
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• pp.161-167
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• 1988

Studies were carried out to examine the effects of simulated acid rain on the various crops of rice, peper, tomato, pumpkin, egg plant, potato, soybean, radish, cucumber, common pea, sweet potato, corn, lettuce, chinse cabbage, spinach, under the condition of the rains of pH 3.0. The rain was adjusted to pH 4.0, 3.0, 2.0 with sulfuric acid, and soybeans were exposed with the various pH levels, eighteen times every other days. The symptoms of damage, ratios of destroyed leaf and sulphur content by leaves were investigated. The results obtained were as follows. 1. The exposure to the rain resulted in the reddish brown or white pigment spots in the leaves surface and the colour was developed red and darker along the edge of spots. 2. Most crops were affected with acid rain of pH 3.0 at which the amount of chlorophyl was decreased. 3. The spinach, chinese cabbage, lettuce were sensitive to the acid rain, however, the peper, tomato pumpkin were resistance to it. 4. The content of chlorophyl was decreased with increasing leave injury. 5. The sulphur content in leave was increased with increasing acidity of the rain, however the yield was decreased.

• Journal of Environmental Science International
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• v.19 no.12
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• pp.1323-1334
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• 2010

The effect of nitric oxide (NO) on antioxidant system and protective mechanism against oxidative stress under UV-B radiation was investigated in leaves of maize (Zea mays L.) seedlings during 3 days growth period. UV-B irradiation caused a decrease of leaf biomass including leaf length, width and weight during growth. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated UV-B stress induced growth suppression. NO donor permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem II than in non-treated controls under UV-B stress, suggesting that NO has protective effect on chloroplast membrane in maize leaves. Flavonoids and anthocyanin, UV-B absorbing compounds, were significantly accumulated in the maize leaves upon UV-B exposure. Moreover, the increase of these compounds was intensified in the NO treated seedlings. UV-B treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in maize leaves, while NO donor prevented UV-B induced increase in the contents of malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that NO serves as antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, catalase (CAT) and ascorbate peroxidase (APX) in maize leaves in the presence of NO donor under UV-B stress were higher than those under UV-B stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3- oxide (PTIO), a specific NO scavenger, to the maize leaves arrested NO donor mediated protective effect on leaf growth, photosynthetic pigment and free radical scavenging activity. However, PTIO had little effect on maize leaves under UV-B stress compared with that of UV-B stress alone. $N^{\omega}$-nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), significantly increased $H_2O_2$ and MDA accumulation and decreased antioxidant enzyme activities in maize leaves under UV-B stress. This demonstrates that NOS inhibitor LNNA has opposite effects on oxidative resistance. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative stress induced by UV-B radiation and thus confer UV-B tolerance.

• Korean Journal of Food Science and Technology
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• v.2 no.1
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• pp.121-126
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• 1970

The utilization of soybean milk has lasted for past several thousand years, mostly in Orient as a Precious food or as a substitute for cow's milk. There are several hundred varieties in soybean that is called Glycine max Merryl There are three typical varieties, Yellow, Black and Green. However, these are due to pigment in soybean cuticle while their chemical constituents are similar (Table 2). Soybean milk is constituted of protein, fat and carbohydrate of soybean, and these constituents are extracted by hot water. Thus becomes emulsion which is highly digestible and nutritious for human diet. However, it was not found any report on the water extractability comparison between two different varieties Black cuticle soybean which is common in India and Yellow cuticle soybean which is common in Korea. Also there was no report on the comparison on the yield and organoleptic quality derived by varied process. Also several attempts were carried out to improve nutritional value as well as acceptability by use of food additives. A model of continuous soybean milk plant was introduced.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.236-243
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• 2012

The leaf growth and physiological characteristics of Forsythia saxatilis were investigated at six natural habitats under different light intensities in Bukhansan in order to figure out an appropriate growth environment for conservation and restoration of F. saxatilis that is Korean endemic plant designated as rare and endangered species. Relative light intensities (RLI) at six habitats showed from 10% to 78% of the full sun. Leaf length, leaf width, leaf area and dry leaf weight of population under highest relative light intensity (78%) were the highest. The ratio of dry leaf weight to leaf area increased with the increase of RLI. The content of photosynthetic pigments such as chlorophyll a, b and carotenoid were the highest at 78% of RLI, whereas the ratio of total chlorophyll to carotenoid content reduced according to the increase of RLI. Photosynthetic parameters, such as photosynthetic rate, also increased with the increase of RLI. The total nonstructural carbohydrate (TNC) was 1.5 times higher at 78% of RLI than that at 10% of RLI and the total soluble sugar (TSS) was the highest at 78% of RLI. In conclusion, leaf characteristics and physiological characteristics have high positive correlation with light intensity. Therefore, light condition should be primarily considered to improve growth and physiology characteristics of F. saxatilis under low light intensity.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.290-290
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• 2017

Rice (Oryza sativa L.) is one of the most consumed staple food crop which is energy source as carbohydrate and also is considered as the important antioxidant sources including various phenolic compounds. According to the increasing demand of healthy life, the concern to antioxidant also is increasing because of its health-promoting effect. Phenolic compounds are one of the plant secondary metabolites class, which shows various benefits to preventing or treating chronic diseases. In this study, we have measured the total phenol content from total 647 rice samples using the Floin-Ciocalteau method, and then were selected 30 rice genetic resources classified with high, middle, and low group on the basis of total phenol content. The average of the total phenol content of each group was high-group ($6892.9{\pm}488.5{\mu}g\;GAE/g$) > middle-group ($1428.1{\pm}76.0{\mu}g\;GAE/g$) > low-group ($97.6{\pm}11.4{\mu}g\;GAE/g$). The selected rice samples were analyzed with LC-MS/MS to find the composition and concentration of individual phenolic in rice grain. High-group and middle-group contained large amounts of protocatechuic acid and (+)-catechin whereas low-group showed limited amount. Among high-group samples, rice samples with black pericarp color (IT 174089, IT 220079, and IT 259958) had high content of peonidin-3-O-glucoside. Further, these black rice samples were special since polydatin, rarely found stilbenoid in rice grain, was detected. Overall, both the sum of phenolic acid and the sum of flavonoid were high-group > middle-group > low-group. Also, each group exhibited different phenolic compositions; high-group consisted of flavonoid more than phenolic acid, middle-group and low-group was comprised of phenolic acid rather than flavonoid, and non-pigmented rice was composed by fully phenolic acid. The total phenol content had positive relationships with the sum of phenolic compound (r = 0.64), the sum of flavonoid (r = 0.74) at the significance level of p < 0.0001. In addition, protocatechuic acid and quercetin showed positive correlation with above phenolic composition parameters; in order, r = 0.98, 0.65 for protocatechuic acid and r = 0.73, 0.78 for quercetin (p < 0.0001). In conclusion, the total phenol content assay showed the possibility of utilization as a phenolic composition indicator in rice grain. Also, this result was suggested study pigment on other material.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.152-156
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• 1994

The purplish red pigment from the roots of Lithospermum erythrorhizon, a Korean edible wild plant, has been investigated concerning it's value as a natural colorant for Korean traditional foods. An attempt was made to isolate pigments and define their characteristics. Two compounds of isobutylshikonin and acetylshikonin were identified by melting point determination and spectra of UV, IR, and $^{1}H-NMR$. To examine the utility of these naphthoquinone pigments for foods, the effect of various pH values on stability were determined over a period of storage. Buffered solutions of acetylshikonin and isobutylshikonin at pH 3 and 5 showed stable purplish red. The absorption maxima if acetylshikonin and isobutylshikonin over the range of pH 3 to 7 were 518 nm and 520 nm, respectively. A bathochromic shift to 588 nm at pH 10 was observed on these two naphthoquinone pigments. Sensory evaluation was performed with acetylshikonin and isobutylshikonin of identical absorbance. These two pigments revealed purplish red color in Munsell system.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.134-142
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• 2008

This work aims to obtain basic information for seed propagation of Hydrangea serrata for. acuminata. The germination percentage of the seeds taken on 15 November, 30 December, and 23 January was $90.0{\pm}4.16%$, $84.4{\pm}5.52%$, and $88.9{\pm}2.40%$, respectively. This suggest that seeds of Hydrangea serrata for. acuminata are non-dormant seeds. The optimum temperature for germination was $25^{\circ}C$ and light was necessary. Most of the growth parameters (shoot and leaf length, stem diameter, root length, no. of roots, T/R ratio, and fresh and dry wts.) were significantly greater at $25/20^{\circ}C$ and $25^{\circ}C$ than at the other temperatures. Low T/R ratio at relatively cool temperatures (15 and $20^{\circ}C$) was caused by suppressed top growth. In light quality treatment, red light (RL) significantly enhanced stem elongation. The greatest photosynthetic pigments (total chl, chl a/b, and carotenoid) were observed in seedlings grown in blue light (BL), followed by seedlings grown in RL+BL. When blue light was added, higher pigment contents were found. Effect of plug cell size (50, 72, 128, 162 and 200 cells) on the growth of seedlings was investigated. The highest top growth was observed in seedlings grown in 50 cell trays, followed by seedlings grown in 72, 128, 162, and 200 cell trays. However, there was no significant differences between 162 and 200 cell trays. Especially, smaller size leaves were observed in seedlings grown in smaller cell trays (lower volume and high plant density).