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        검색결과 2,998

        2901.
        2004.12 서비스 종료(열람 제한)
        Calmodulin, a Ca2+-binding protein, has no enzyme activity. It combines with Ca2+ and makes variable proteins to an active form. Calmodulin 2 is a ubiquitous protein in plants. To investigate the defense mechanism against various stresses, a clone encoding a calmodulin 2 protein was isolated from a cDNA library prepared from taproot mRNAs of Codonopsis lanceolata. The cDNA, designated CICAM2, is 719 nucleotides long and has an open reading frame of 450 bp with a deduced amino acid sequence of 149 residues. The deduced amino acid sequence of CICAM2 showed a high similarity with calmodulins of P. x hybrida (P27163) 97%, N. tabacum (BAB61908) 97%, S. tuberosum (AAA74405) 96%, Z. mays (CAA74307) 92%, C. richardii (AF510075) 93%, M. truncatula (AAM81203) 91%, and G. max (P62163) 91%. The transcriptional expression of the CICAM2 gene, was gradually increased by the CaCl2 treatment. Whereas its expression And it was gradually decreased in the cold stress treatment.ent.
        2902.
        2004.12 서비스 종료(열람 제한)
        To investigate the defense mechanism against the abiotic stress, a cDNA clone encoding a CuZn superoxide dismutase (CuZnSOD) protein was isolated from a cDNA library prepared from tabroot mRNAs of Codonopsis lanceolata. The eDNA, designated ClSODCc, is 799 nucleotides long and has an open reading frame of 459 bp with a deduced amino acid sequence of 152 residues. The deduced amino acid sequence of ClSODCc matched to the previously reported CuZnSODs. Consensus amino acid residues (His-45, -47, -62, -70, -79, -119 and Asp-82) were involved in Cu-, Cu/Zn-, and Zn- binding ligands. The deduced amino acid sequence of ClSODCc showed high homologies (82%-86%) regardless of species. Expression of ClSODCc by oxidative stress was increased up to 1 h after treatment and declined gradually. Much earlier and stronger expression of ClSODCc was observed in the cold stress treatment.
        2903.
        2004.11 KCI 등재 서비스 종료(열람 제한)
        Resveratrol, which is both a phytoalexin with antifungal activity and a phytochemical associated with reduced cancer risk and reduced cardiovascular disease, is synthesized in a limited number of plant species including peanut. Resveratrol synthesis is catalyzed by the enzyme stilbene synthase including resveratrol synthase (RS). Resveratrol synthase gene (RS3) obtained from peanut, Arachis hypogaea, Fabaceae has been transferred into chinese foxglove, Rehmannia glutinosa by using Agrobacterium mediated transformation. RS t-DNA introduced to chinese foxglove (R. glutinosa L) by transformation and its reaction product, resveratrol-3-O-β-D-glucoside was isolated and characterized using HPLC. Also its biological effects was tested in inhibition of the lipid peroxidation of mouse LDL by glycosylated stilbenes derivatives obtained from transgenic plants. Resveratrol-3-O-β-D-glucoside isolated from transgenic R. glutinosa L. showed antimicrobial activity of the growth inhibition zone against Escherichia coli and Salmonella typhimurium. Therefore, this compound can be contributed to be useful as a phytoalexin for plant health as well as a phytochemical for human health.
        2904.
        2004.11 KCI 등재 서비스 종료(열람 제한)
        Rehmannia glutinosa shows a high level of resistance to the non-selective herbicide paraquat. To characterize the antioxidant enzyme system of R. glutinosa, we comparatively examined the responses of antioxidant enzymes to UV, wounding and a general elicitor yeast extract in R. glutinosa and soybean. The levels of enzyme activities of the two plant species were drastically different between those per fresh weight (general activity) and per protein (specific activity) bases. The general activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and glutathione reductase (GR) were lower, but that of ascorbate peroxidase (APX) was higher in R. glutinosa than in soybean. The specific activities of the enzymes, however, were about two- to seven-fold higher in R. glutinosa than in soybean, except that of CAT, which was about 12-fold higher in soybean. The general and specific enzyme activities of R. glutinosa relative to those of soybean showed a consistent increase in responses to the stresses only in SOD. The specific activities of SOD and APX were higher in R. glutinosa in all stress treatments. The results might suggest a relatively higher contribution of SOD and APX to the stress tolerance.
        2905.
        2004.11 KCI 등재 서비스 종료(열람 제한)
        A survey was conducted during April~May 2004 to determine the occurrence and population density of plant-parasitic nematodes in ginseng (Panax ginseng C.A. Meyer) growing fields, in major ginseng growing regions of Chungbuk, Chungnam, Gyeongbuk and Kyongki provinces. The survey revealed presence of eleven species of plant-parasitic nematodes namely, Criconemoides morgensis, Ditylenchus destructor, Helicotylenchus dihystera, Meloidogyne incognita, M. hapla, Paratylencgus lepidus, Pratylenchus penetrans, Psilenchus hilarulus, Trichodorus similis, Tylenchorhynchus claytoni and Xiphinema americanum. Frequency and density of each species were highly variable. M. incognita and M. hapla were the predominant species, their infestation observed in 46.3 and 39.4% fields with an average density of 78~254 and 76~211 nematodes per 300 cm3 soil, respectively. Whereas, T. similis and X. americanum were rarely observed; only in 2.3 and 1.8% of surveyed fields and their density was 10~17 and 7~10 individuals per 300 cm3 soil, respectively. They are recorded herewith for the first time from ginseng fields of Korea. In nematode-infestated fields, stunted plant growth with chlorotic leaves, and wilted plants were observed in patches.
        2906.
        2004.09 KCI 등재 서비스 종료(열람 제한)
        The response of dissolved oxygen (DO) concentrations caused significant change in root number, root length, coleoptile length, shoot length and leaf age of seedlings. The genotypic difference in the effect of DO also highly significant (P<0.01) for all of the seedling traits. The number and length of root were extremely inhibited at the condition of 0.39~pm0.09 DO concentration. While the coleoptile elongated markedly in the lowest DO concentrations, the shoot did not develop. The root growth was improved slightly at the 1.39~pm0.27mg L-1 , however, there were no difference among genotypes at these two low DO concentrations. As the DO concentration become higher, the growth of root and shoot was improved remarkably. Root number, root length and shoot length was significantly different between 20~;and~;30~circC in DO rich and normal conditions, the development of those traits were apparently accelerated in high water temperature, however those traits of seedlings in DO deficiency were not different between the two temperatures except for shoot length. On the other hand the coleoptile length was not affected by the stagnant water temperature; it was stimulated by the low DO concentration. The competition of DO was greater as the seedling density was increased in the stagnant water, therefore the seedlings grown under high density have long and white coleoptiles, and the growth of roots and shoots was retarded severely.
        2910.
        2004.05 KCI 등재 서비스 종료(열람 제한)
        The objectives of this study were to establish the genetic transformation system of stilbene synthase in Rehmannia glutinosa. Resveratrol, which is both a phytoalexin with antifungal activity and a phytochemical associated with reduced cancer risk and reduced cardiovascular disease, is synthesized in a limited number of plant species including peanut. Resveratrol synthesis is catalyzed by the enzyme stilbene synthase including resveratrol synthase (RS). Stilbene synthase gene (RS3) obtained from peanut, Arachis hypogaea, Fabaceae has been transferred into chinese foxglove, Rehmannia glutinosa by using Agrobacterium mediated transformation. PCR analysis with RS3 primer confirmed that the targeted gene was introduced into the plant genome, 904 bp in size. Further analyses of identification of transformation using developed other molecular techniques and transgenic plants that RS t-DNA introduced to chinese foxglove (R. glutinosa L) and its reaction product, stilbene such as resveratrol will be isolate and characterize using NMR, MS, and HPLC.
        2911.
        2004.05 KCI 등재 서비스 종료(열람 제한)
        Hairy roots were induced from Korean ginseng (Panax ginseng C. A. Meyer) root explants and studied for their gene expression. A total of 3,000 ESTs (expressed sequence tags) from ginseng hairy root were determined and about 2,700 ESTs have a length of readable sequence, which result in 1,352 unique ESTs sequences. The 879 ESTs showed significant similarities to known nucleotide or amino acid sequences in other plant species, which were divided into eleven categories depending upon gene function. The remaining 473 sequences showed no significant matches, which are likely to be transcripts or to be matched to other organisms. The results indicated that the analysis of the ginseng hairy root ESTs by partial sequencing of random cDNA clones may be an efficient approach to isolate genes that are functional in ginseng root in a large scale. Our extensive EST analysis of genes expressed in ginseng hairy root not only contributes to the understanding of the dynamics of genome expression patterns in root organ but also adds data to the repertoire of all genomic genes.
        2912.
        2004.04 서비스 종료(열람 제한)
        The establishment of an efficient protocol for plant regeneration and micropropagation from leaf explant cultures of Chicory, Cichorium intybus L. var. sativus. is reported. Callus formation rate appeared 100% from explant in all growth regulators, but calli formed in the prensence of naphthaleneacetic acid (NAA) were appeared very compact and non-embryogenic state. The regenerated shoots were obtained from leaf explant cultures on solid MS medium containing different concentrations of cytokinins and auxin. The highest number of shoots (5.7) per explant and shoot growth (2.8cm) was obtained on MS medium containing 0.1 mg BAP L-1 and 0.1 mg NAA L-1 . Indole acetic acid was the most suitable auxin for root formation among three auxins tested. 2,4-D had no effect on shoot and root formation.
        2913.
        2004.04 서비스 종료(열람 제한)
        Allium wakegi was cultured shoot tip in the condition of light culture. The Allium wakegi added plant growth regulator was observed of plant regeneration and bulblet formation. Callus Induction and growing rate was the best of 78% when added alone 2,4-D 0.5mg/L. In the formation of shoot, its regeneration rate was 96% when added BA 0.5mg/L in the light culture condition. When BA 0.5mg/L and NAA 0.5mg/L mixed and BA 0.5 mg/L and NAA 1.0mg/L mixed, the rates were 99% and 97% respectively, and these conditions were suitable for forming shoot. In the formation of roots, when added NAA 2.0mg/L in the light culture condition, the regeneration rate was 90.6 % and the roots were abnormal. When added NAA 1.0mg/L, the rate was 82 % and the highest. In the formation of bulbs, when BA 05mg/L and NAA 1.0mg/L mixed, the root generantion and its size in the bulbs was the best compare to other treatment experiments.
        2914.
        2004.03 KCI 등재 서비스 종료(열람 제한)
        The shipping industry can be explained by a growing process of concentration and centralization of tonnage. A few largest shipping company control a great deal of shipping tonnage in the total tonnage through the process of concentration and centralization of tonnage in shipping over time. It confirms that a decreasing number of operators take an increasing quantity of tonnage in the total tonnage. Thus, the extremely dualistic structure (extremely unequal distribution of tonnage) are shown not only in the shipping industry in a given country but also in liner shipping in the world In this paper, the two countries, that is, Korea and Egypt, are compared considering the absolute size of tonnage and shipping policy in tenn., of concentration and centralization of tonnage in shipping. In order to measure the degree of concentration of tonnage in shipping, the quantitative measurements; the Lorenz curve and Gini coefficient are introduced. But it should be supplemented with the qualitative measures of tonnage in a given country.
        2915.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        The long-period gravity wave, the wave period from some ten seconds to some minutes, induces not only the big sway of a ship moored and berthed in the harbor due to the horizontal long-distance motion of a water but also strong exfoliated flow and vortices near the harbor entrance. They muse serious problems on the safety navigation of vessels entering and leaving the harbor, but this gravity wave has not been searched sufficiently yet. Then it is quite important to reveal the characteristics of this long-period gravity wave ana to solve various problems induced by this wave. The long-period gravity wave measurement system with arrayed buoys installed the kinematic GPS was already proposed, which provides the precise propagating direction of the long-period gravity wave. In this paper, the observation results of the wave measurement system are shown by the MUSIC method And the propagating wave direction was estimated precisely enough in comparison with other results used other method.
        2916.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        It can be said that the relationship between the maneuvering ability of operators and the navigational environment affects the safe degree of navigation in the collision avoidance situation. In order to reduce the occurrence probability of accident and to maintain the safety, it is necessary to clarify the relationship between human behavior and navigational environment. In this study, therefore, we analyzed and discussed the relationship between the maneuvering characteristics and the safety focused on human behavior as a fundamental factor of marine accidents using ship handling simulator and questionnaire. As a result, we concluded that navigational environment changes variously and the maneuvering ability of operators also varies with the navigational environment, and the ship handling characteristics strongly affect the occurrence probability of accident.
        2917.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        This experiment was conducted to know the characteristics of kernel growth as affected by various temperature regimes during grain filling using the varieties Hwaseongbyeo, Ilpumbyeo and Chucheongbyeo. The rice plants tested were grown in the natural condition at 1/5000a Wagner pots until flowering. After flowering, the rice plants were moved to controlled temperature conditions in a phytotron. The minimum/maximum daily temperature in the phytotron was controlled by 12/18, 15/21, 18/24, 21/27, and 24/30~circC , respectively. The grain weights were measured every three days after treatment. The mean daily kernel growth rate during active grain filling period showed different responses among varieties under various temperature regimes. The kernel growth rate of Chucheongbyeo was seriously reduced as temperature regimes were decreased. However, that of Ilpumbyeo was not influenced so critically. Ilpumbyeo showed some advantages in grain filling under low temperature regimes compared to Chucheongbyeo. The lag phase in grain filling of Chucheongbyeo was the longest among tested varieties, followed by Hwaseongbyeo under daily mean temperature regime of 15~circC . Kernel weight of Ilpumbyeo increased fast in early grain filling phase under low temperature. This characteristic may be favorable for grain filling in temperate zone where the daily mean temperature is drastically dropped during grain filling period. Regression analysis with kernel growth rate and temperature showed the estimated critical low temperature for grain filling among varieties were 9~circC , 12~circC , 13~circC in Ilpumbyeo, Hwaseongbyeo and Chucheongbyeo, respectively. Under moderate temperature the duration of grain filling of Ilpumbyeo was longer than that of Chucheongbyeo. However, Under low temperature that of Ilpumbyeo was more favorable than Chucheongbyeo.
        2918.
        2003.12 서비스 종료(열람 제한)
        The shoot tip and young leaf of Rhodiola sachalinensis were cultured to invest the plant growth regulator condition for callus induction, shoot and root regeneration. When the shoot tip was sterilized in 2.0% of NaOCl for 20min., the contamination rate was the lowest. And the survival rate of the culture material was good in carbenicillin 500mg/L treatment group. Callus was obtained from shoot tip and young leaf segments. NAA 0.1-1.0mg/L and 2,4-D 0.1-0.5mg/L alone treatment were shown to have a good response on callus induction from shoot tip culture. In the case of young leaf culture, NAA and 2,4-D 0.1-0.5mg/L alone treatment were good in callus induction. In culturing shoot tip NAA 0.5mg/L and BA 0.5mg/L, NAA1.0mg/L and BA 0.lmg/L combination treatment was good in shoot regeneration. The regenerated shoots were rooted on MS medium supplemented with NAA and BA combination treatment. Especially, NAA 1.0mg/L and BA 0.1mg/L combination treatment was effective for root regeneration.
        2919.
        2003.12 서비스 종료(열람 제한)
        Ginseng(Panax ginseng C.A. Meyer) is a perennial herbaceous plant which grows very slowly. It takes about 3 to 4 years from seeding to collecting the ripe seeds and the ginseng propagation is very difficult. and so, it is very difficult to breed ginseng plant. Ginseng tissue culture was started from at 1960, and ginseng commercial product by in vitro callus culture was saled, however upto now, regenerants were not planted to soil normally. Recently, plant genetic engineering to produce transgenic plants by introducing useful genes has been advanced greatly. In a present paper, transformation of ginseng plants was achieved by co-cultivation with Agrobacterium harboring the binary vector coding Proteinase-II gene, which confer resistant or tolerant to insect pests, The binary vector for transformation was constructed with disarmed Ti-plasmid and with double 35S promoter. The NPT II gene and introduced genes of the transgenic ginseng plants were successfully identified by the PCR. Especially the transgenic ginseng plants were regenerated using new techniques such as repetitive single somatic embryogenesis.
        2920.
        2003.12 서비스 종료(열람 제한)
        Genetic diversity of 45 tea accessions from Korea, Japan, China and Taiwan was investigated by using RAPD analysis. Out of the eighty primers screened, twenty primers generated 99 polymorphic bands with a polymorphic rate 87.0%. The size of the amplified fragments ranged from about 3,138 bp to 520 bp. By cluster analysis, all of the 45 accessions can be grouped into five groups. Over 90% of the 32 Korean accessions belonged to group II, III, IV and V. Moreover, newly developed Korean cultivars (accession no. 13, 14 and 15) belonged to very different group compared with any other Korean accessions. Among the Korean accessions, the minimum genetic similarity 0.500 was obtained between accession no. 17 and 37 and the largest genetic similarity 0.912 between no. 20 and 21.