• Journal of Plant Biology
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• 제34권4호
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• pp.311-316
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• 1991

The origin of cambial initials from procambium was studied in the seedling root of Acer saccharinum. In transverse view, the first periclinal divisions of procambial cells occurred just outside of each early metaxylem and resulted in meristematic strips. As root development progressed, the division activities appeared subsequently outside of each late metaxylem and then in pericycle cells opposite the four protoxylem poles. Eventually, such meristematic strips were connected completely each other. Thus, a nearly rectangular shaped meristematic layer in outline was formed outside the xylem in a whole root transectioned. In tangential section, early procambium showed a homogeneous structure consisted of uniform short cells with transverse end walls. However, some of the procambial cells did elongate, whereas others divided transversely. The former become more elongate, tapered, and vacuolated. Finally, they differentiated into fusiform initials. Short cells consisting axial strands divided continuousely in transverse plane and became ray initials, while some short cells elongated and transformed into long cells. The early ontogeny of vascular cambium in Acer saccharinum root was interpreted to be established by a gradual process.

• Journal of Plant Biology
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• 제34권4호
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• pp.274-281
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• 1991

The relationship between elongation of hypocotyl and its vascular transition was studied with seedling of Glycine max. the hypocotyl elongation proceeded acropetally from the base of hypocotyl toward the cotyledonary node. The vascular transition did not occur in the basal region of the hypocotyl, which did not nearly elongate, with exarch radial vascular bundles. However, the vascular transition was almost completed at the middle part of the hypocoty, more or less elongated, with endarch collateral vascular bundles. Such bundles also appeared in the uppermost region of the hypocotyl, in which the elongation was the most striking. These results suggested that the vascular transition was related to the hypocotyl elongation and that the transition of primary vascular system in Glycine max seedling was established by rather rapid process. Our observations of the serial sections from root to hypocotyl revealed that the vascular system through the root-hypocotyl-cotyledon was a unit, to which one of the epicotyl that did not participate in transition was superimposed.

• Journal of Plant Biology
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• 제33권4호
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• pp.285-292
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• 1990

In order to elucidate the formation of reaction tissues during the transition from primary to secondary growth, the developmental anatomy was conducted in the first internode of Ginkgo biloba seedling in horizontal position. The righting of the horizontal first internode took place at the middle portion and gradually proceeded to the base during the primary growth. Reaction tissues were formed corresponding to the righting movement in the horizontal first internode. During the transition from primary to secondary growth, compression wood was gradually developed on the lower side only. The anatomical features of compression wood also extended longitudinally to the lower side of the vertical portion where it coincided with the lower side of the horizontal first internode occurs acropetally from basal to apical portion. Eventually, some of the anatomical features of compression wood occurred at the primary growth. And the typical compression wood is gradually established during the secondary growth. On the other hand, the lower side tracheid and ray were longer and higher than those of the upper side in the horizontal first internode. However, difference in the width of ray was not observed between the lower and upper sides.

• 한국작물학회지
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• 제8권1호
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• pp.117-119
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• 1970

담배품종 Yellow special A의 약을 개량 RM-1964 배지에 배양하였던바 배양 약 3주일 후에 약의 내부로부터 유식물이 생겨나고 이들은 그후 정상적인 생육을 하여 약 6개월후에 개화되었다. PMC의 M.에서는 24개의 1가염색체를 가진 것이 제일 많고 2가염색체는 PMC당 0.8이었다.

• 생명과학회지
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• 제6권2호
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• pp.87-93
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• 1996

귀화식물인 미국자리공의 군락 구조와 무기환경요인을 추적하였다. 서식지 식생은 Pinus densiflora, persicaria perfoliata, Miscanthus sinensis, Smilax china, Rubus crataegifolius, Paederia scandens, Rosa multiflora, Commelina communis, Carex lancelolatl가 우점 하였으며 파괴된Pinus densiflora 아극상 감림군략에 침임하여 적응한 형태였다. 서식지 토양의 속성은 pH 4.6의 높은 산도, 높은 중금속과 유기물 함량이 특징적이었으며 이는 전형적인 황지식물군락의 환경요인이었다. 생장조절실 내에서 수행한 제한요인 처리에 의해 나타나는 유식물의 피해반응은 인공산성비에 의한 pH2.0과 500Lux의 광도에서 나타났으며 일시위조점은 pF2.6-2.7에서, 그리고 영구위조점은 pF2.8-2.9에서 각각 나타났다.

• Journal of Plant Biology
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• 제36권3호
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• pp.275-279
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• 1993

The early ontogeny of the vascular cambium in the hypocotyl of Eucommia ulmoides seedling was studied anatomically. In transverse view, the procambial cells repeated periclinal divisions and then gradually differentiated into vascular cambium; however, in the transectional plane, it was difficult to reveal the origin of cambial initials. In tangential view, the early procambial cells repeated periclinal divisions and then the procambium consisted of homogeneous short cells. Some cells in late procambium did not show transverse divisions, but elongated continuously. Thus, the procambium showed a heterogeneous structure: The long cells became fusiform initials with tapering end walls and the short cells differentiated into ray initials. Conclusively, the two types of cambial initials were gradually originated from the homogeneous cells at the early procambial stage, and they consisted vascular cambium.

• Journal of Plant Biology
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• 제31권2호
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• pp.131-141
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• 1988

The effects of decursinol and decursin on chloroplast-mediated electron transport and phosphorylation in barley seedlings were investigated in comparison with coumarin in the dark or light. The changes of CP-complexes were also studied. Decursinol, decursin and coumarin caused marked inhibitory effects on germination of seed and electron transport and phosphorylation activity of seedlings. The following order of inhibitory effectiveness was exhibited; decursinol>coumarin>decursin. Loss of chlorophyll and decrease of electron transport activity were retarded in the dark, but were reversely accelerated in the light by these three chemicals. The changes of CP-complex patterns were also similar to effects on chlorophyll content and the electron transport activity. These opposite effect in the dark and light suggest that these three chemicals act as natural growth retardants rather than cytokinins or growth inhibitors.

• Journal of Plant Biology
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• 제27권4호
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• pp.241-251
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• 1984

The present study investigated the effects of triacontanol (TRIA) on plant growth and peroxisomal enzyme activities in radish seedlings. The optimum concentration of TRIA with respect to radish seedling bioassay was decided to 1.0mg $1^{-1}$. In comparison to untreated controls (including Tween 20 treatment), 1.0mg $1^{-1}$ TRIA treatment caused an increase in seed germination rate and root growth, but no stimulation in hypocotyl growth. Chlorophyll accumulation in cotyledon during carly development stage increased rapidly, and degradation of chlorophyll in later stage due to the cotyledon senesence was noticeably retarded. Increase of soluble protein content in cotyledon at early period of development was observed. Isocitrate lyase and catalase activity was not significantly different in both the treated and the untreated plants. But, glycolate oxidase activity was inhibited by TRIA down to 20% against controls. Also, the increase of the activity of peroxidase, a leaf-senescence marker enzyme, was continuously retarded over control for 8 days of development. Based on above results, TRIA was found to be active in both the growth and the peroxisomal enzyme activities of radish seedlings.

• Journal of Plant Biology
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• 제29권4호
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• pp.243-254
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• 1986

The enzyme patterns and the food storage changes in radish (Raphanus sativus L. cv. Taewang) cotyledons during seedling development were studied. The radish seeds were germinated for 8 days at $25^{\circ}C$ under light (7, 000 lux) or dark condition. The lipid and protein contents per seed were 4.3 mg and 2.85 mg respectively. In 8-day-old light-grown seedling, the lipid and protein contents per cotyledon pair were 1.5 mg and 2.08 mg; in 8-day-old dark-grown seedling, they were 0.8 mg and 1.24 mg respectively. The heterotrophic phase of seedlings continued for 3 days after sowing and followed by autotrophic phase (3~6 day) and senescence phase (6~8 day). The food storage function decreased in response to time course. During heterotrophic phase, the activities of glyoxysomal enzymes (malate synthetase, isocitrate lyase, and catalase) were high at 2~3 day. Those patterns were somewhat more prominent in darkness. During the autotrophic phase, the activities of peroxysomal enzymes (glycolate oxidase and catalase) increased at 4~5 day.

• Journal of Plant Biology
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• 제36권2호
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• pp.171-176
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• 1993

Protein kinase C, a protein related in PI cascade, was partially purified from the cytosol protein of etiolated plants of Glycine max by DEAE-52 cellulose chromatography and phenylsepharose chromatography. When the DEAE column was eluted with 0-0.8 M linear gradient KCl, tow fractions were found that increased the phosphorylation of histon H1 about five and nine-fold in the presence of 5 $\mu\textrm{g}$/mL phosphatidylserine and 0.5 $\mu\textrm{g}$/mL diolein, respectively. These fractions were used as DEAE pool. The reaction eluted with relatively high concentration of KCl was loaded on phyenylsepharose column with 5 mM CaCl2 and eluted with 1 mM EGTA. A fraction contained the protein kinase C, which increased the phosphorylation of the histon H1 was fractionated. To determine the molecular weight of PKC, the fraction eluted from phenylsepharose column was analyzed by 5~15% polyacrylamide gel electrophoresis after concentrated with the Amicon membrane (YM10). That revealed two bands corresponding to 60 and 65 kGy by silver staining of the gel, respectively.