• Korean Journal of Plant Resources
• /
• v.14 no.2
• /
• pp.116-123
• /
• 2001

The non-enzymatic antioxidants and antioxidant enzyme from the extracts of Parthenocissus tricuspidata PLANCH. were examined in order to utilize natural product for cerchemopreventive agents. The antioxidant potential and enzyme activities on plant positions in the extracts of Parthenocisuss tricuspidata PLANCH. showed considerable differences. The antioxidant activity of the leaf extracts by Ethyl acetate fractions of Parthenocisuss tricuspidata PLANCH. was the highest among three positions ($7.57\mu\textrm{g}/m\ell$). The highest activities showed in S-5 (in leaf), S-4 (in stem) and S-3 (in root) fraction by Silicagel column chromatography and the antioxidant activity showed, in purified extract of each positions, $7.06\mu\textrm{g}/m\ell$ (in leaf), $6.99\mu\textrm{g}/m\ell$ (in stem) and $12.39\mu\textrm{g}/m\ell$ (in root) respectively. The activities of DPPH by LH-20 column chromatography revealed much higher than those by silica-gel column chromatography. These were identified as the phenolic compounds known as antioxidant compounds such as Benzoic acid(Gallic acid), 1-methyl-3-(2-phenylethen) benzene, phloroglucinol and 1,2-dihydroxy-4-(1-propyl)benzene by GC/MS. POD activities in the stem and root were higher than in the leaf. SOD activity was highest in the leaf, stem and root activity was comparatively low. Especially, SOD activity in leaf was over 2 times higher than root.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.5
• /
• pp.310-315
• /
• 2000

Alfalfa (Medicago sativa L.) plants have been reported to contain water-soluble substances that are autotoxic as well as allelopathic. Laboratory experiment through a petri-dish assay with imbibed seeds was conducted to evaluate both autotoxic and allelopathic effects of alfalfa leaf extracts on the germination and early seedling growth of alfalfa, red clover, crested wheatgrass, and Russian wildrye. Alfalfa seed germination was delayed dependent on extract concentration, with no difference in final germination at 72 hours. Root growth of alfalfa was stimulated up to 14% above control at very low concentrations of both leaf and stem extracts of alfalfa and was significantly reduced at extract concentration of more than 0.5g dry tissue/L (${gL}_{-1}$). Leaf extracts were generally more autotoxic for root growth than were stem extracts. Hypocotyl growth was not affected by all the concentrations of both leaf and stem extracts. Root length of legumes was more sensitive to the autotoxic chemicals from leaf extracts than was germination or shoot length. Hypocotyl growth of two legume plants and plant height of two grasses were not influenced by extracts. Seed germination and root growth of legumes were more inhibited by aqueous extracts of alfalfa leaf than were those of grasses. This result indicates autotoxic effect of alfalfa leaf extracts seems to be greater than allelopathic effect.

• Korean Journal of Medicinal Crop Science
• /
• v.4 no.3
• /
• pp.255-260
• /
• 1996

This study was conducted to investigate the characteristics of aboveground plants and red ginseng of polystem ginseng in 6 years of age having two or more stems in a plant. Total leaf weight and area of polystem ginseng were larger, while its stem diameter, and the leaf weight and area of the big­gest stem in each plant were decreased with increase the stem numbers in a plant. The ratio of shoot weight to root weight in the polystem ginseng with three or more stems was higher than that in the monos­tem ginseng and the polystem ginseng with two stems, In ginseng plants with no more than 2 stems, there were positive correlations between root weight and total leaf weight, and leaf area, but not between leaf weight and area of the biggest stem. Inner cavity and inner white, limiting factors for redginseng quality grade, occurred more in tri-stem ginseng than mono- and di-stem one. Percentages of Heaven (1st grade) and Earth (2nd grade) red ginseng in tri-stem ginseng were decreased compared with mono stem and di-stem ginseng.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.3 no.3
• /
• pp.8-11
• /
• 2000

The experiment was carried out in order to the effects of NAA on rooting of stem cutting of leaf variegated Aster glehni, dwarf type of Achillea sibirica and Solidago virga-aurea var. asiatica native to Korea. Higher rooting percentage(85%) of Aster glehni, promoted root number and root length of Achillea sibirica were obtained by basal dip treatment with $1,000mg{\cdot}L^{-1}$ NAA for 3 hours on late June. Percent rooting of the Solidago was not enhanced, but root number and root length were promoted by basal dip treatment with $100mg{\cdot}L^{-1}$ NAA.

• Journal of Ginseng Research
• /
• v.3 no.2
• /
• pp.105-112
• /
• 1979

Effect of gibberllin on the breaking of bud dormancy of root and growth of aerial parts were investigated under laboratory and field condition for the prolongation of shoot growth duration, shortening of fruit bearing age and the increase of root yield. Drop application of GA (0.5ml of 50ppm) on rhizome of one year old root broke bud dormancy better than by low temperature. Soaking for one hour of one year old roots which wintered in the field in GA (50-200ppm) greatly accelerated the emergence of new buds while kinetin was only effective at low level (50ppm). GA substantially increased stem length in early stage and petiole length later on while kinetin increased stem diameter. Under the field condition with polythylene film tunnel (PET) in early spring the soaking in GA (50ppm for 1 hour) of rhizome of 4 year old root with replanting and dropping GA (50ppm, 1ml) on rhizome without replanting brought earlier emergence (29days) in comparison with that in the usual field. PET alone caused 14 day-early emergence. GA increased the length of stem and petiole only in early stage and replanting decreased only petiole length in later stage. Soaking in GA with replanting caused the Pronounced decrease in peduncle length, percentage of (ruin set and dry weight of reproductive organ (fruits and peduncle). Dropping without replanting showed significant decrease only in dry weight of reproductive organ. Fruit maturing was 20 days earlier than in usual held with little difference between GA and PET. It is well expected that GA could be used for early emergence of bud, shortening of root dormancy period, thinning of fruit and higher root yield according to application amount and methods.

• Korean Journal of Plant Resources
• /
• v.12 no.4
• /
• pp.269-275
• /
• 1999

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi, and seonmi, whose source and sink are different, were cultivated at different planting densities, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem and leaf and tuberous root weight by planting density and defoliation rate of sweet potato varieties was different. Stem and leaf weight per m$^2$ increased along with dense planting by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number per m$^2$ was the most at 75$\times$20cm planting density, showing seonmi the most number. The number of stem and leaf and tuberous root increased along with the lowered rate of defoliation. In case of 75$\times$10cm and 75$\times$20cm planting density, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem and leaf and tuberous root number was low as defoliation rate increases. The tuberous root and total dry weight matter was the most at 75$\times$20cm planting density. The increase and decrease of source synchronized with those of sink at 75$\times$10cm and 75$\times$20cm, however the relationship occurred less at 75$\times$30cm.

• Journal of Environmental Science International
• /
• v.17 no.9
• /
• pp.1015-1021
• /
• 2008

This study was performed to examine the accumulated concentrations (conc.) of cadmium (Cd) in the organs of Arabidopsis thaliana grown in the soil with different conc. of Cd. The official standard conc. of Cd of pollutant exhaust notified by the Korean ministry of environment (0.1 mg/L) and ten times higher (1 mg/L) and fifty times higher (5 mg/L) conc. and no Cd in the soil as control were used for this investigation. The results showed that accumulated conc. of Cd in the stems of plant grown in the soil with different conc. (0.1, 1 and 5 mg/L) were increased 9%, 24% and 286% respectively, compared with normal plant stem. The accumulated conc. of Cd in the leafs of plant gown in the soil with official standard conc. and conc. ten times higher and conc. fifty times higher were increased 3%, 22% and 453%, respectively, compared with normal plant leaf. The accumulated conc. of Cd in the root of plant grown in the soil with 0.1 and 1 mg/L conc. of Cd were increased 6%, 19%, respectively, compared with normal plant root. However, it was observed about 84% of increased accumulation of the Cd in the root of plant, when highest (5 mg/L) conc. was used. The accumulated conc. of Cd in the different organs of Arabidopsis thaliana were increased according to increase of Cd conc. in the soil. When official standard conc. and ten times higher conc. of Cd were used, the accumulated conc. of Cd increased average 6%, 21%, respectively, compared with normal plant organ, and the accumulated conc. of Cd between leaf, stem and root were not significant. However, the accumulated conc. of Cd in the plant organs gown in the conc. fifty times higher were increased about 285%, compared with normal plant. In addition, the accumulated conc. of Cd in different organs of Arabidopsis thaliana exhibited wide differences between organs, that is, stem was increased 118% than root, leaf was increased 256%, 64% than root and stem, respectively. These results show that accumulated conc. of Cd in Arabidopsis thaliana with highest (5 mg/L) conc. of Cd in soil, were much higher in the leaf than the stem or root in proportion to the conc. of Cd contaminated within the soil.

• Journal of Ginseng Research
• /
• v.8 no.1
• /
• pp.57-64
• /
• 1984

In order to clarify an effect of seedling weight on the growth pattern of ginseng, seedlings ranged from 0.4g plant to 1.8g plant were transplanted, and then the characters of 5- and 6-year-old ginseng were investigated. The characters of root and leaf, such as length and diameter of main root, root weight, leaf area, and leaf dry weight of 5- and 6-year-old ginseng originated from large seedlings were superior as compared with those from small seedlings, and percentage of missing plant was increased with the increase of seedling weight. There were, however, no significant difference in stem length, stem dry weight, number of seeds per plant and number of palmate leaves and leaflets per plant in 5- and 6-year-old ginseng and these characters were not affected by the weight of seedings transplanted. Root field per unit area was higher in seedings of above 0.6g/plant than in small seedlings.

• Molecules and Cells
• /
• v.45 no.10
• /
• pp.695-701
• /
• 2022

Homeostatic regulation of meristematic stem cells accomplished by maintaining a balance between stem cell self-renewal and differentiation is critical for proper plant growth and development. The quiescent center (QC) regulates root apical meristem homeostasis by maintaining stem cell fate during plant root development. Cell cycle checkpoints, such as anaphase promoting complex/cyclosome/cell cycle switch 52 A2 (APC/C^CCS52A2), strictly control the low proliferation rate of QC cells. Although APC/C^CCS52A2 plays a critical role in maintaining QC cell division, the molecular mechanism that regulates its activity remains largely unknown. Here, we identified SCF^FBS1, a ubiquitin E3 ligase, as a key regulator of QC cell division through the direct proteolysis of CCS52A2. FBS1 activity is positively associated with QC cell division and CCS52A2 proteolysis. FBS1 overexpression or ccs52a2-1 knockout consistently resulted in abnormal root development, characterized by root growth inhibition and low mitotic activity in the meristematic zone. Loss-of-function mutation of FBS1, on the other hand, resulted in low QC cell division, extremely low WOX5 expression, and rapid root growth. The 26S proteasome-mediated degradation of CCS52A2 was facilitated by its direct interaction with FBS1. The FBS1 genetically interacted with APC/C^CCS52A2-ERF115-PSKR1 signaling module for QC division. Thus, our findings establish SCF^FBS1-mediated CCS52A2 proteolysis as the molecular mechanism for controlling QC cell division in plants.

• Journal of Ginseng Research
• /
• v.5 no.2
• /
• pp.85-91
• /
• 1981

Ginseng seeds were gathered from 3,4,5 and 6 years of age and were classified into four qroups (below 4mm, 4∼5mm, 5∼6mm and above 6mm in across sieve). They were sown in seedling bed and some characters were investigated in each qroup of seed size. 1. The distribution of seed size of below 4mm, 4-5mm, 5-6mm and 6mm were 23.7%, 60.8%, 12.4% and 4.5%, respectively. 2. The ratio of seed coat dehiscence was not affected by seed size but emergence ratio and emerging vigor were superior in large seed. 3. The large seed showed superiority in stem length, stem diameter, leat and also in root length, root diameter and root weight. but diseased root was not affected by seed size. The effect of age(seed harvest) was not significant on all those characters.