• 한국약용작물학회지
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• 제20권3호
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• pp.171-176
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• 2012

This study was conducted to investigate the effect of atmosphere-leaf vapor pressure deficit (VPD) in Allium microdictyon Prokh. and Allium ochotense Prokh. The vapor pressure deficit (VPD) was rapidly increased with increasing temperature and decreasing relative humidity. Taken as a whole, the stomatal transpiration reaction was slightly late with increading of VPD. Maximum photosynthetic rate at high-VPD condition was 5.98 ${\mu}mol$ $CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ in Allium microdictyon, which was a little lower than 6.59 ${\mu}mol$ $CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ in Allium ochotense, respectively. After 2 p.m, stomatal transpiration of Allium microdictyon at the high VPD condition were rapidly decreased. Ci/Ca began to decline sharply at 8 a.m and showed the lowest value at 2 p.m, The results showed that Ci/Ca decreased with being used $CO_2$ in the mesophyll intercellular space for photosynthesis. In high VPD condition, The water potential values showed the highest at 5 a.m, and the lowest at 1 p.m in high VPD condition. The water saturation deficits (WSD) in high VPD condition showed about 1.5 times higher than in low VPD condition. The results indicated that physiological activities in Allium microdictyon is more limited from high VPD conditions.

• 한국응용곤충학회지
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• 제19권2호
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• pp.67-72
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• 1980

우리나라에 발병하고 있는 생강모자이크 바이러스병의 기생범위, 물리화학적 성질, 혈청검정 및 전자현미경적 관찰을 조사하였다. 생강의 초기병징은 황록반문을 일으키고 후기에는 위축현상 및 괴경의 소구화를 이룬다. 포장이병율은 약 $43\%$이었다. 즙액전염, 접구전염(core grafting)이 이루어지며, 동부, 오이 Chenopodium amaranticolar, N. tabaccum var. Havana를 비롯하여 23종의 CMV감수성 식물에 병증을 나타낸다. 희석한계점은 $10^{-4}\~10^{-5}$ 범위이고, 온도한계활성점는 $65\~70^{\circ}C$사이이다. 혈청반응은 CMV 항혈청과 양성으로 나타난다. 전자현미경에 의한 바이러스립자의 크기는 $28\~32m\mu$의 구형이다. 이병엽육조직의 세포질 속에는 구형바이러스입자의 밀집상과 유리되어 있는 입자도 관찰되었다. 이상을 종합하여 볼 때 생강에 모자이크병을 일으키는 바이러스는 CMV군에 속하는 바이러스로 믿어진다.

• Journal of Ginseng Research
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• 제40권2호
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• pp.176-184
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• 2016

Background: Wild ginseng, Panax ginseng Meyer, is an endangered species of medicinal plants. In the present study, we analyzed variations within the ribosomal DNA (rDNA) cluster to gain insight into the genetic diversity of the Oriental ginseng, P. ginseng, at artificial plant cultivation. Methods: The roots of wild P. ginseng plants were sampled from a nonprotected natural population of the Russian Far East. The slides were prepared from leaf tissues using the squash technique for cytogenetic analysis. The 18S rDNA sequences were cloned and sequenced. The distribution of nucleotide diversity, recombination events, and interspecific phylogenies for the total 18S rDNA sequence data set was also examined. Results: In mesophyll cells, mononucleolar nuclei were estimated to be dominant (75.7%), while the remaining nuclei contained two to four nucleoli. Among the analyzed 18S rDNA clones, 20% were identical to the 18S rDNA sequence of P. ginseng from Japan, and other clones differed in one to six substitutions. The nucleotide polymorphism was more expressed at the positions 440-640 bp, and distributed in variable regions, expansion segments, and conservative elements of core structure. The phylogenetic analysis confirmed conspecificity of ginseng plants cultivated in different regions, with two fixed mutations between P. ginseng and other species. Conclusion: This study identified the evidences of the intragenomic nucleotide polymorphism in the 18S rDNA sequences of P. ginseng. These data suggest that, in cultivated plants, the observed genome instability may influence the synthesis of biologically active compounds, which are widely used in traditional medicine.

• Journal of Plant Biology
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• 제34권1호
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• pp.37-43
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• 1991

Nicotiana ($NR^{-}/SR^{+}$)과 N. glutinosa간 전기적 (0.5 MHz의 AC와 2 ms 동안 1 kV DC) 원형질체 융합에서 선발은 1.2mg/ml의 streptomycin이 첨가된 $MSNO_3$ 배지를 통하여 가능하였으며, 이 융합세포의 분열이 지속되어 형성된 녹색 세포괴를 얻었다. 이 녹색 세포괴에서 재분화된 4개의 식물 계통들은 꽃과 잎에서 모식물체의 특징을 보였으며, 엽조직의 peroxidase 동위효소 유형 분석에서도 양쪽 모식물체의 특성을 갖고 있었다. XhoI의 제한효소 절단에 의해 융합식물체 계통의 엽록체 DNA의 분석에서도 융합체 식물계통들은 N. tabacum과 N. glutinosa에서 공통되는 단편과 모식물체 유래 단편을 보였고, 이 융합식물계통들 중 한 계통은 9개의 공통 단편에 N. tabacum의 1개 단편, N. glutinosa의 2개 단편이 추가되어 있는 유형을 보여 N. tabacum과 N. glutinosa의 엽록체 게놈을 모두 소유하고 있다는 것을 보여주었다.

• Applied Microscopy
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• 제24권4호
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• pp.13-31
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• 1994

피자식물내 엽육조직 미세구조연구의 일환으로 형태해부학적으로 매우 다른 특성을 지닌 국화과 Dubautia속 식물 3종(Dubautia scabra var. leiophylla, D. knudsenii, D. scabra var. leiophylla, D. knudsenii)의 엽육조직이 연구되었다. 부모종 엽육조직의 형태해부학적 특성과 그들의 잡종 엽육조직세포의 분화 정도를 추정하기 위하여 palisade mesophyll내의 chloroplasts, microbodies, mitochondria 및 grana내의 thylakoid membrane system, phytoferritin-like structures, plastoglobuli와 starch grain 등 엽록체 내부의 초미세구조 형질들을 중점적으로 비교 분석하였다. 잡종의 엽육조직세포들은 형태해부학적 엽육형질 및 thylakoidal membrane system 등의 형질에서 부모종 엽육조직의 중간적 특성 (intermediacy)을 나타내어 전형적인 bilateral inheritage를 보여주었으며, thylakoid membrane number/granum, phytoferritin-like structures, starch grain의 분포 등에서는 어느 한 부모종 형질과 더 유사하게 관찰되었다. 미소체 및 미토콘드리아는 대체로 비슷한 양상으로 관찰되었고 phytoferritin-like structures는 국화과 식물 엽록체내에서 처음 보고되는 미세구조이다.

• 식물조직배양학회지
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• 제22권2호
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• pp.111-114
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• 1995

지치 (Lithospermum erythorhizon SIEB, et ZUCC)의 잎조직으로부터 유도한 캘러스를 현탁배양하여 약리성 지방산인 ${\gamma}$-linolenic acid (GLA)를 생산하는 기술을 확립하고자 탄소원, 질소원, 생장조절제의 영향을 조사하였다. 캘러스 유도는 1.0 mg/L 2,4-D 단용첨가시 가장 왕성하였다. Sucrose 88mM농도에서 세포생육이 가장 왕성하고 총지방산(TFA)중 GLA비율이 높아 단위건물중당 TFA함량이 가장 낮았음에도 flask당 GLA생산량은 가장 많았다. 질소원으로서 potassium nitrate농도증가는 세포생장 및 지방산함 량 및 GLA함량을 증가시켰으며 최고 처리농도인 56.3 mM 에서 최고수준을 나타냈다. IAA 첨가는 배양세포 생장량을 증가시켰고 2,4-D는 배양세포내의 총지방산 함량을 높이는 결과를 나타내었으나, kinetin과 BA는 세포생육에 저해적 영향을 나타냈다. $10^{-7}$ M ABA는 캘러스생장을 유의적으로 증가시켰으며 TFA 및 GLA함량도 증가시켰으나 현탁배양세포의 생육과 지방산 축적에는 저해적으로 작용하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.323-327
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• 1992

An experiment was conducted to determine whether there were any apparent differences in the microbial population, colonization pattern and digestion of guinea grass in situ, between cattle and swamp buffalo. Percentage losses in dry matter (DM), nitrogen (N) and neutral detergent fibre (NDF) of guinea grass were significantly (p<0.01) higher when incubated in the rumen of buffalo than in cattle. Buffalo also showed significantly (p<0.05) faster degradation rates than cattle for each grass component (DM, N, DNF). Light microscopy and SEM examination of the incubated grass materials showed that there were no apparent differences in the pattern of bacterial and fungal invasion and colonization of the grass materials between cattle and buffalo. Attachment of bacteria and fungal zoospores on the grass fragments occurred at 15 min after rumen incubation. After 3 h of rumen incubation, dense population of bacteria was observed in the thin-walled mesophyll and parenchyma tissues, whereas root-like fungal rhizoids were observed in both thin-walled and thick-walled cells. By 6 h, eroded zones were apparent in the thin-walled tissues and in thick-walled tissues with profuse rhizoids. After 24. 48 and 72 h of rumen incubation, most thin-walled tissues were degraded leaving mostly the thick-walled tissues. The predominant bacteria were the curved rods resembling Butyrivibrio sp., the thick rods resembling Fibrobacter sp., the diplococcoids resumbling Ruminococcus sp. And spirochetes. Fungi were predominantly those with spherical or oval sporangia. Fusiform sporangia with acuminate apices which resembled Ruminomyces sp. Were of lesser occurrence. Few protozoa were found on the grass fragments at all incubation times.

• Plant Biotechnology Reports
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• 제4권4호
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• pp.281-291
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• 2010

The rice CHLH gene encodes the $Mg^{2+}$-chelatase H subunit, which is involved in chlorophyll biosynthesis. Growth of the chlorophyll-deficient oschlh mutant is supported by mitochondrial activity. In this study, we investigated the activity of mitochondrial respiration in the illuminated leaves during oschlh seedling development. Growth of mutant plants was enhanced in the presence of 3% sucrose, which may be used by mitochondria to meet cellular energy requirements. ATP content in these mutants was, however, significantly lowered in light conditions. Low cytosolic levels of NADH in illuminated oschlh mutant leaves further indicated the inhibition of mitochondrial metabolism. This down-regulation was particularly evident for oxidative stressresponsive genes in the mutant under light conditions. Hydrogen peroxide levels were higher in oschlh mutant leaves than in wild-type leaves; this increase was largely caused by the impairment of the expression of the antioxidant genes, such as OsAPXl, OsRACl, and OsAOXc in knockout plants. Moreover, treatment of mesophyll protoplasts with ascorbic acid or catalase recovered ATP content in the mutants. Taken together, these results suggest that the light-mediated inhibition of mitochondrial activity leads to stunted growth of CHLH rice seedlings.

• Molecules and Cells
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• 제39권10호
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• pp.768-775
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• 2016

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dissection followed by the derivation of central cell protoplasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

• Journal of Plant Biotechnology
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• 제31권2호
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• pp.145-149
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• 2004

목본류 생리학 연구에 있어서 중요한 수종인 Peace 포플러의 기초 연구자료를 얻고자 본 실험을 실시하였다. 액아 마디를 BA 0.2 mg/L처리된 MS 배지에 배양하여 shoot의 증식시 나타나는 과수화 된 shoot를 정상 shoot와 비교하였다. 과수화 된 shoot는 진한 녹색을 띠고, 잎은 두껍고 휘어져 있으며 투명하였다. 또 줄기는 정상적인 줄기보다 두껍고 길이가 짧았다. 조직학적 관찰 결과 과수화 된 잎은 책상조직의 발달이 부진하였으며 정상적인 잎에 비하여 책상조직과 해면조직 그리고 표피 세포 모두 불규칙하고 세포간극의 크기가 큰 것으로 나타났다. 또한 과수화 된 잎의 기공은 크기가 커서 단위면적 당 밀도가 낮았으며 공변세포와 그 주변 세포들이 변형되어 있었다. 과수화된 shoot의 직경은 정상적인 것보다 큰 것으로 나타났는데 이것은 피층과 수층 세포의 비대에 따른 것으로 관찰되었다. 한편 과수화 된 줄기는 정상 줄기에 비해 목질화 발달이 미약하여 형성층 구별이 어려웠다.