• 원예과학기술지
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• 제33권5호
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• pp.625-632
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• 2015

Drought is a severe abiotic stress that affects global crop production. A drought model was created for 'Toyonoka' Fragaria ${\times}$ ananassa, and the effects of drought stress on contents of proline, sugars, and antioxidant enzyme activities were investigated. Strawberry transplants with identical growth were chosen for the experiments and the randomized design included four replications (10 plants per block). The experimental sets differed in the moisture level of the culture medium relative to the range of moisture content as follows: control, 70-85%; mild drought stress, 50-60%; moderate drought stress, 40-50%; and severe drought stress, 30-40%. Drought stress was imposed by limiting irrigation. Plants were sampled and physiological parameters w ere measured on 0, 2, 4, 6, 8, and 10 days after the commencement of droughts tress. The water potential of strawberry leaves decreased in the plants under mild, moderate, and severe stress during the course of the water stress treatment and exhibited a significant difference from the control. Strawberry leaves subjected to drought stress had higher accumulation of proline, sugars, and malondialdehyde, and higher activities of superoxide dismutase, peroxidase, and catalase than leaves of control plants. Malondialdehyde levels increased in parallel with the severity and duration of drought stress. By contrast, antioxidant enzyme activity displayed dynamic responses to drought stress, first increasing and subsequently decreasing as the severity and duration of drought stress increased. These results suggest that strawberry plants respond to drought stress by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. These biochemical response changes may confer adaptation to drought stress and improve the capacity of plants to withstand water-deficit conditions.

• Journal of Photoscience
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• 제9권2호
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• pp.162-165
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• 2002

Rice is widely cultivated in various regions throughout Asia. Over a five-year period, we investigated the effects of supplemental UVB radiation on the growth and yield of Japanese rice cultivars in the field. The findings of that study indicated that supplemental UVB radiation has inhibitory effects on the growth and grain development. Furthermore, we investigated the sensitivity to UVB radiation of rice cultivars of 5 Asian rice ecotypes, and found that rice cultivars vary widely in UVB sensitivity. The aim of our study is improving UVB resistance in plants by bioengineering or breeding programs. In order to make it, there is need to find the molecular origin of the sensitivity to UVB. Cyclobutane pyrimidine dimer (CPD) is major UV-induced DNA lesions. Plants possess two mechanisms to cope with such DNA damage. The first is the accumulation of UV-absorbing compounds. Our previous data showed that the steady-state CPD levels in leaves of rice grown under chronic radiation in any culture were not so greatly influenced by the increased UV-absorbing compounds content, although there was a significant positive correlation between the CPD levels induced by challenge UVB exposure and the UV-absorbing compounds content. The other is the repair of DNA damage. Photorepair is the major pathway in plants for repairing CPD. We found that the sensitivity to UVB could seriously correlate with the low ability in CPD photorepair in rice plants. These results suggest that photo lyase might be an excellent candidate for restoration by way of selective breeding or engineering in rice.

• 생약학회지
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• 제23권4호
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• pp.268-275
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• 1992

We studied to screen medicinal plants having hepatoprotective activity with the primary cultured rat hepatocytes intoxicated with carbon tetrachloride cytotoxicity. The lowest concentration and treatment time of carbon tetrachloride giving the greatest intoxication to the primary cultured hepatocytes were observed in 10mM and 60 minutes, respectively. GTP and GOT activity of culture broth of the primary cultured rat hepatocytes intoxicated by $CCl_4$ cytotoxicity at this condition were increased 135.9% and 178.3% compared with that of the primaries cultured hepatocytes not treated with $CCl_4$, respectively. This increased GPT activity was inhibited by glycyrrizin, which was known to have hepatoprotective activity, and the inhibition activity was dependent on the concentration of glycyrrhizin. Forty species among the extracts obtained from 117 species of medicinal plants were shown to have the hepatoprotective activity. Among these 40 species, Prunus persica, Scutellaria baicalensis, Astragalus membranaceus, Tribulus terrestris, Caragana chamlagu, Acanthopanax sessiliflorum and Achyranthes japonica were indicated a lower GPT activity than that of Glycyrrhiza uralensis containing glycyrrhizin and GPT activity of these were indicated 75.5%, 70.0%, 59.0%, 77.5%, 60.0%, 75.0% and 79.0%, respectively.

• 한국자원식물학회지
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• 제21권2호
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• pp.139-143
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• 2008

다섯 종류의 가지과 식물을 대상으로 elicitor에 의해 생합성 되는 capsidiol의 함량을 측정하고 생합성에 관련된 P450 효소의 활성과 관련 유전자 발현을 조사하였다. 고추, 피망 및 담배는 capsidiol의 생합성에 관련된 두개의 유전자인 cyclase와 P450 유전자가 세포내에 존재하였고, elicitor의 처리에 의하여 유전자의 발현이 유도되고 효소의 촉매가 이루어 졌다. 가지세포에는 두개의 유전자가 게놈상에 존재하지만 P450 유전자는 발현되나, cyclase 유전자의 발현은 나타나지 않았다. 감자에는 capsidiol의 생합성에 관련된 P450 및 cyclase 유전자 모두가 존재하지 않은 것으로 나타났다. 본 실험에 사용된 P450과 cyclase 유전자는 식물이 정상상태에 있을 때는 전혀 발현되지 않으나 elicitor에 의해 특이적으로 유도 되는 특징을 보였고, 식물체 조직이나 기관별로 다양한 발현 양상을 보였다.

• Journal of Forest and Environmental Science
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• 제30권4호
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• pp.405-411
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• 2014

Wild Korean ginseng has been recognized as highly precious medicine since ancient times. Nowadays, the population of wild ginseng in the forest of Korean peninsula is very rare due to indiscreet harvest. In this work, we investigated the plant regeneration via somatic embryogenesis from embryogenic callus of old wild ginseng (more than 50 years-old) and compared the features of plants regenerated from 5-years old and 50 years-old ginseng. Induction of embryogenic callus from adventitious roots of 50 year-old wild ginseng required 83 weeks of culture, but only 10 weeks were sufficient for 5 year-old ginseng. Height and width of plants derived from the old wild ginseng was smaller and slender compared to the plantlets derived from 5 year-old ginseng. Total chlorophyll contents was 2-6 time lower in plantlets regenerated from 50 year-old wild ginseng than those from 5 year-old ginseng, but anthocyanin content was higher in 50 year-old ginseng. Our results revealed that plants regenerated from old wild ginseng have different morphological and physiological characters probably due to age-dependent phenomenon.

• 식물조직배양학회지
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• 제28권6호
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• pp.353-357
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• 2001

인삼의 자엽과 callus에 Biolistic system을 이용한 비선택성 제초제인 bialaphos에 대한 내성을 갖게 하는 PAT 유전자의 형질전환효율 향상 및 형질전환체의 유전분석에 관한 실험을 수행하였다. 자엽의 경우에는 형질전환율이 약했지만 callus의 경우에는 target distance 9 cm, rupture disk-macro-carrier gap distance를 1/3"로 했을 때 가장 양호한 형질전환 결과를 보였다. 형질전환된 인삼식물체에서 PAT 및 NPT 유전자의 존재 여부를 확인하기 위해서 PCR을 수행한 결과 정상 식물체서는 전혀 PCR product가 형성되지 않은 반면 형질전환체 모두에서 PAT (약 300 bp)와 NPT (약 800 bp) 유전자의 band를 확인하여 각각의 유전자가 삽입되어 PAT 및 NPT IIgene이 도입된 형질전환체임을 확인할 수 있었다. 있었다.

• Animal cells and systems
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• 제6권1호
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• pp.59-64
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• 2002

To restore the forest ecosystem severely damaged by air pollution around industrial complexes, plants tolerant to the polluted environment were selected by transplant and pot culture experiments. A restoration plan by arranging those tolerant species was prepared based on the ecological diagnostic results on an area that requires restoration. Transplant experiment in Ulsan and Yeocheon areas, the representative industrial complexes in Korea, selected eight tolerant species of Quercus aliena, Q. acutissima, Q. dentata, Q. mongolica, Q. serrata, Ligustrum japonicum, Styrax japonica, and Poncirus trifoliata. Cultivation in the polluted soil transported from the Ulsan and Yeocheon industrial complexes chose five tolerant plants of Q. aliena, Q. acutissima, Q. serrata, Styrax japonica, and Alnus firma. A plan to restore the forest ecosystem of Mt. Dotjil, which experienced the severest ecosystem degradation in the Ulsan industrial complex, was prepared by applying those tolerant species along with treatment for soil amelioration. Arrangement of the tolerant species was designed by considering their ecological characteristics including distribution range on topography and shade tolerance. Soil amelioration was focused on the improvement of fertility and moisture conditions.

• Molecules and Cells
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• 제39권9호
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• pp.705-713
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• 2016

The efficiency of Agrobacterium-mediated transformation in plants depends on the virulence of Agrobacterium strains, the plant tissue culture conditions, and the susceptibility of host plants. Understanding the molecular interactions between Agrobacterium and host plant cells is crucial when manipulating the susceptibility of recalcitrant crop plants and protecting orchard trees from crown gall disease. It was discovered that Arabidopsis voltage-dependent anion channel 1 (atvdac1) mutant has drastic effects on Agrobacterium-mediated tumorigenesis and growth developmental phenotypes, and that these effects are dependent on a Ws-0 genetic background. Genetic complementation of Arabidopsis vdac1 mutants and yeast porin1-deficient strain with members of the AtVDAC gene family revealed that AtVDAC1 is required for Agrobacterium-mediated transformation, and there is weak functional redundancy between AtVDAC1 and AtVDAC3, which is independent of porin activity. Furthermore, atvdac1 mutants were deficient in transient and stable transformation by Agrobacterium, suggesting that AtVDAC1 is involved in the early stages of Agrobacterium infection prior to transferred-DNA (T-DNA) integration. Transgenic plants overexpressing AtVDAC1 not only complemented the phenotypes of the atvdac1 mutant, but also showed high efficiency of transient T-DNA gene expression; however, the efficiency of stable transformation was not affected. Moreover, the effect of phytohormone treatment on competence to Agrobacterium was compromised in atvdac1 mutants. These data indicate that AtVDAC1 regulates the competence of Arabidopsis to Agrobacterium infection.

• Journal of Plant Biotechnology
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• 제29권3호
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• pp.199-207
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• 2002

The tropane alkaloids hyoscyamine (its racemic form being atropine) and scopolamine are used medicinally as anticholinergic agents that act on the parasympathetic nerve system. Because they differ in their actions on the central nervous system, currently there is a 10-fold higher commercial demand for scopolamine, in the N-butylbromide form, than there is for hyoscyamine and atropine combined. Several solanaceous species have been used as the commercial sources of these alkaloids, but the scopolamine contents in these plants often are much lower than those of hyoscyamine. For this reason there has been long-standing interest in increasing the scopolamine contents of cultivated medicinal plants. Naturally occurring and artificial interspecific hybrids of Duboisia have high scopolamine contents and are cultivated as a commercial source of scopolamine in Australia and other countries. Anther culture combined with conventional interspecific hybridization also has been used to breed high scopolamine-containing plants in the genera Datura and Hyoscyamus, but without much success. The use of recombinant DNA technology for the manipulation of metabolic processes in cells promises to provide important contributions to basic science, agriculture, and medicine. In this review, I introduce on the enzymes and genes involved in tropane alkaloid biosynthesis and current progress in metabolic engineering approaches for tropane alkaloid, especially scopolamine, production.

• Mycobiology
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• 제51권3호
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• pp.186-194
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• 2023

In July 2021, wilting symptoms were observed in adult and seedling hemp (Cannabis sativa L. cv. Cherry Blossom) plants grown in a greenhouse. As the disease progressed, yellowing and wilting symptoms on the leaves developed, resulting in whole plant death. In seedling plants, typical damping-off symptoms were observed. To identify the pathogen, the roots of diseased plants were sampled, surface sterilized, and cultured on potato dextrose agar (PDA) media. From the culture, 4 different fungal isolates were recovered and purely cultured. Each fungal isolate showed distinct growth shapes and color development on malt extract agar, oatmeal agar, sabouraud dextrose agar, and PDA media. Microscopic observation and molecular identification using ribosomal DNA internal transcribed spacer sequencing identified them as 3 Fusarium spp. and 1 Thielaviopsis paradoxa. Additional sequencing of elongation factor 1-alpha and b-tubulin regions of 3 Fusarium spp. revealed that 2 of them are Fusarium solani, and the other one is Fusarium proliferatum. To examine which isolate can act as a causal agent of wilt disease of hemp, each isolate was tested for their pathogenicity. In the pathogenicity test, F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3, but not T. paradoxa AMCF4, were able to cause wilting disease in hemp seedlings. Therefore, we report that F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3 as causal agents of Fusarium wilt of hemp plants. To our knowledge, this is the first report of the wilt disease of C. sativa L. caused by Fusarium spp. in Korea.