• Journal of Plant Biology
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• v.36 no.1
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• pp.29-34
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• 1993

Observation was made on early ontogeny of vascular cambium in the cotyledonary node of Pinus koraiensis seedling in order to clarify the cambial ontogeny of the node which was hardly elongated. In transverse view, the derivatives by the early periclinal divisions at the outer region of the procambial strands differentiated to protophloem with establishing a certain degree of radial seriations. Later, some cells in the central region of the procambial strands begin divide periclinally, eventually the cells, differentiate gradually to the vascular cambium. In tangential view, early procambium is consisted of homogeneous short cells with transverse end walls which are tansformed into the long cells and short cells gradually. The long cells continue intrusive growth and the short cells repeat transverse division. Finally, the long and short cells differentiated to cambial fusiform initials and ray initials respectively. In tangential section, the differentiation pattern of cambial initials resembles that of the stem of Ginkgo biloba. But in transverse view, the characteristics in the origin of vascular cambium of the cotyledonary node resembles that of root. The vascular cambium in cotyledonary node is completed after eleven prophylls were formed.

• Journal of Plant Biology
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• v.36 no.4
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• pp.357-362
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• 1993

To elucidate the origin of secondary growth in the rhizome of B. ternaturn, the developmental changes of vascular cambium was observed in ultrastructural features. The vascular cambium was gradually differentiated from procambium as in seed plants, but the cambial activity did not persist very long so that the cambial cells became a dormant state like fossil cryptogams. Dense cytoplasm of procambial cells became progressively sparse during the growth, and the tiny vesicles were fused to form numerous small vacuoles and then a few large vacuoles. These gradual changes and the occurrence of storage materials which was associated with the developmental stages might support the progressive differentiation of the cambial cells. In addition, the cessation of cambial activity could be indicated by the facts that late vascular cambial cells accumulate large lipid bodies and show very small peripheral cytoplasm and unlikely thickened cell wall, compared to other meristematic cells. Therefore. the vascular cambium showed the characteristics of both seed plants and fossil cryptogams from the view point of cambial ontogeny and activity.tivity.

• Journal of the Korean Wood Science and Technology
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• v.33 no.4 s.132
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• pp.1-8
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• 2005

The initiation and cessation of cambial activities were investigated to find out the growth characteristics of the major species growing in Chuncheon, Korea. The division of cambial zone in Pinus densiflora and Pinus koraiensis began from the middle of March through the end of March. The activity of cambial zone in P. densiflora and P. koraiensis was vigorous from the end of May through the middle of July. During this period the number of cells increased rapidly in radial direction. However, the number of cells in P. densiflora was gradually increased. The division of cambial zone in ring-porous wood, such as Quercus mongolica and Robinia pseudoacacia began in the middle of March, before the formation of vessel. The division of cambial zone in diffuse-porous wood, such as Cornus controversa and Prunus sargentii, began in early April, and then the formation of vessels began after one to three weeks. It was considered that the cambial zone in softwood was ceased from the beginning of November, whereas cambial activities in hardwood ceased in the middle of October. Consequently, the formation of growth ring was different among the species, even though the trees were grown under the same conditions.

• Journal of Plant Biology
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• v.36 no.1
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• pp.35-42
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• 1993

This study deals with the effect of dwarf growth for the wood and the structural changes of cambium in Pinus koraiensis subjected to water stress. The length and wall thickness of tracheary elements in dwarf trees was shorter and thicker than that in normal trees. The redial width and cell number of the annual rings are narrower and smaller in dwarf trees than those in normal trees. In serial tangential sections, the frequency of anticlinal division is low and loss of cambial initials is small in dwarf trees. The length of cambial initials in water deficit, trees are slightly shorter than that in normal trees, and the instructive growth of cambial initials during differentiation of xylem mother cells is inactive in dwarf trees. Thus, it is interpreted that the shortening of tracheary elements in dwarf trees is due to the fact that the length of cambial initials are shortened and the intrusive growth of those during differentiation of xylem mother cells is inactive. The structural variations in the wood of naturally occurring dwarf trees are similar to those of trees subjected to artificial water stress. Therefore, it is suggested that the variation of xylem element in dwarf trees are related to water conditions.

• Journal of Plant Biology
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• v.36 no.3
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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 the Korean Wood Science and Technology
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• v.43 no.4
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• pp.411-420
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• 2015

Despite of the same species there is a difference in the tree shape and its wood property due to quantitatiVe and qualitatiVe differences in wood cells by the intra-annual cambial actiVity. The purpose of this study was to proVide the fundamental database of intra-annual cambial seasonal actiVity for red pine in Sokwang-ri and Anmyondo for the determination of their wood qualities. As the results of intra-annual cambial actiVity, the initiation of cambial actiVity of red pine in the plots with Age Class V in Sokwang-ri was in the middle of April and it was at the beginning of April in all plots in Anmyondo. Only the plots with Age Class IX in Sokwang-ri showed relatiVely late initiation of cambial actiVity as between middle of May and middle of June. Except one plot with Age Class IX in Sokwang-ri all plots in both sites showed the same cessation of cambial actiVity as between middle and end of October. According to intra-annual cambial actiVity, the duration of cambial actiVity in Sokwang-ri is shorter than that of Anmyondo. On the other hand, the number of cell diVision of cambial actiVity in Sokwang-ri was more than those of Anmyondo. We could establish the database for intra-annual cambial actiVity for Sokwang-ri and Anmyondo to estimate their wood quality.

• Journal of Plant Biology
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• v.37 no.3
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• pp.317-323
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• 1994

The calluses formed on the surface of a quarter-girdled Robinia pseudoacacia stems have been shown to originate from immature xylem cells and preexisting cambial cells. The cellus is not only formed by periclinal and anticlinal divisions of radial cells, but also axial cells. In tangential view, the callus at initial stage showed heterogeneous structure composed of long and short cells and then homogeneous one with short cells. Some cells of homogeneous structure in middle region of callus at early stage is later elongated and others mainly divided in trasverse plane. In the result the homogeneous structure becomes into a heterogeneous one. Subsequently, the long cells in heterogeneous structures elongated further and became fusifrom initials, and the short cells divided transversely became ray initials. The appearence of homogeneous and heterogeneous structure in the callus on debarked stem without organ elongation is almost similar to that of the structure in the procambium of young stem which is elongating extensively. Eventually, the ontogeny of vascular cambium in wound callus resembles that of a young stem grown normally, although the debarked stem does not grow in length but in girth and the young stem elongates activity. These findings mean that the active intrusive growth of short procambial cells occurs during the differentiation of fusiform cambial cells.

• Journal of Plant Biology
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• v.36 no.3
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• pp.251-257
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• 1993

The size variation of the cambial initials and their derivatives, in relation to the increase of girth, in the intact and decapitated stem of Populus euramericana was anatomically studied. In the typical nonstoried cambium of P. euramericana, the cell size of fusiform initials, vessel member, and sieve tube member were gradually increased and thus it reached a maximal state. In the intact plants, the size of the cambial initials and their derivatives was larger then in the decapitated ones. On the other hand, the frequency of anticlinal division of the cambial cells, the rate of the elongation and loss of the daughter initials in the intact plants was higher than in the decapitated ones. The cambium of the intact plants had higher ray compared with that of the decapitated ones. It was interpreted that these results were caused by the decapitation, which could block the supply of certain substances for cell growth such as hormones and metabolites.

• Journal of Ginseng Research
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• v.39 no.4
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• pp.376-383
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• 2015

Background: Panax ginseng has a wide range of biological activities including anti-inflammatory, antioxidant, and immunomodulatory functions. Wild ginseng cambial meristematic cells (CMCs) were obtained from P. ginseng cambium. This study examined the protective mechanism of wild ginseng CMCs against $\small{D}$-galactosamine (GalN)-induced liver injury. GalN, a well-known hepatotoxicant, causes severe hepatocellular inflammatory damage and clinical features similar to those of human viral hepatitis in experimental animals. Methods: Hepatotoxicity was induced in rats using GalN (700 mg/kg, i.p.). Wild ginseng CMCs was administered orally once a day for 2 wks, and then 2 h prior to and 6 h after GalN injection. Results: Wild ginseng CMCs attenuated the increase in serum aminotransferase activity that occurs 24 h after GalN injection. Wild ginseng CMCs also attenuated the GalN-induced increase in serum tumor necrosis factor-${\alpha}$, interleukin-6 level, and hepatic cyclooxygenase-2 protein and mRNA expression. Wild ginseng CMCs augmented the increase in serum interleukin -10 and hepatic heme oxygenase-1 protein and mRNA expression that was induced by GalN, inhibited the increase in the nuclear level of nuclear factor-kappa B, and enhanced the increase in NF-E2-related factor 2. Conclusion: Our findings suggest that wild ginseng CMCs protects liver against GalN-induced inflammation by suppressing proinflammatory mediators and enhancing production of anti-inflammatory mediators.

• Journal of Plant Biology
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• v.34 no.3
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• pp.191-199
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• 1991

This study has been conducted to investigate the developmental changes of cambial initials and their derivatives in relation to the growing girth of tree in Diosypros kaki and Firmiana simplex. In D. Kaki and F. simplex with typical storeyed cambium, increase in the girth of camium occurred by radial anticlinal division in general, however occasionally the increase was companied by pseudotransverse division. The length of fusiform initials, vessel member, and sieve tube member remained relatively constant throughout the secondary growth but that of fiber showed general tendancy to increase with growing girth of tree. During the girth increase of tree, height and number of ray remained constant in D. kaki, however in F. simplex, height of ray markedly decreased while the number of ray per unit area more or less increased. The secondary ray was originated from the segmentation or division of the side or end of fusiform initials.