• Journal of Applied Biological Chemistry
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• v.51 no.3
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• pp.83-87
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• 2008

Tension wood, a specialized tissue developed in the upper side of the leaning stem and drooping branches of angiosperm, is an attractive experimental system attractive for exploring the development and the biochemical pathways of the secondary cell wall formation, as well as the control mechanism of the carbon flux into lignin, cellulose, and hemicellulose. However, the mechanism underlying the induction and the development of the tension wood is largely unknown. Recently, several researchers suggested the possible roles of the plant growth hormones including auxin, gibberellin, and ethylene mainly based on the expression pattern of the genes in this specialized tissue. In addition, expressed sequence tag of Poplar and Eucalyptus provide global view of the genetic control underlying the tension wood formation. However, the roles of the majority of the identified genes have not yet been clearly elucidated. The present review summarized current knowledge on the biosynthesis of tension wood to provide a brief synopsis of the molecular mechanism underlying the development of the tension wood.

• Journal of Plant Biology
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• v.34 no.2
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• pp.137-144
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• 1991

기주식물 (토끼풀, Trifolium repens L.)에 기생하는 실새삼(Cuscuta australis R. Brown)의 흡기내 목부의 개체발생 과정을 광학현미경으로 조사하였다. 흡기의 목부 분화를 암시하는 최초의 해부학적 특징이, 흡기 자체내에서가 아니라, 그 흡기가 형성되어 있는 실새삼 줄기에서 나타났다. 즉 실새삼 줄기의 중심주의 유관속 내부 및 유관속 사이에서 세포분열 활성이 관찰되었다. 이 분열로부터 유도된 세포들은 짙게 염색된 세포질과 뚜렷한 핵을 갖고 있었다. 흡기가 기주조직에 침입하여 생장함에 따라, 실새삼 줄기의 중심주에서 시작된 세포분열 활성은 유관속 사이를 거쳐서 흡기의 기부를 향하여 구정적으로 확장되었다. 이와 동시에, 실새삼 줄기의 목부에 인접해 있던, 짙은 세포질 밀도를 갖는 세포들이 목부요소로 분화하기 시작하였다. 결국, 이미 형성되었던 짙게 염색된 세포들을 따라서 흡기의 목부는 구정적으로 분화하였다. 실새삼 줄기의 중심주에서 일어나는 유조직 세포들의 분열활성 및 이로부터 흡기의 목부 분화를 구정적으로 유도할 수 있는 가능성에 대하여 논의하였다.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.73-81
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• 2016

The Albuginales (Oomycetes) consist of obligate biotrophic pathogens, none of which is culturable on artificial media. This group causes white blister rust disease in diverse angiosperm plants, including many economically important crops such as sunflower, horseradish, rape, radish, spinach, and wasabi. Recent advances in molecular phylogenetic tools and findings of new morphological characters have advanced our knowledge on their diversity, evolution, and systematics. This review introduces the white blister rusts and discusses recent innovations resulting from studies on Albuginales.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.359-366
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• 2000

Epigenetics represents a chromatin-mediated transcriptional repression which plays a control role in both animal and plant development. A number of different mechanisms have been described to be involved in the formation of chromatin structure: especially DNA methylation, nucleosomal histone modification, DNA replication timing, and binding of chromatin remodelling proteins. Epigenetic phenomena include genomic imprinting, dosage compensation of X-chromosome linked genes, mutual allelic interactions, paramutation, transvection, silencing of invasive DNA sequences, etc. They are often unstable and inherited in a non-Mendelian way. A number of epigenetic defects has been preferentially described in floral development. Here, epigenetic phenomena in model angiosperm plants and their corresponding mechanisms are reviewed.

• Journal of Plant Biology
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• v.22 no.1_2
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• pp.45-51
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• 1979

From 32 angiosperm species, pollen surface characters such as sculpture pattern, roughness, oil abundance and stickiness were subjectively scored, and compared with size and weight of the grains, and pollination mechanisms. There was a linear relationship between size and weight of the grains. Animal-pollinated grains showed significantly higher roughness, oil abundance and stickiness than wind-pollinated grains. In the former, the grain size was highly correlated with roughness and oil abundance. No such relationship was found in the latter. It was suggested, therefore, that the large the animal-pollinated grains, the greater is the stickiness required, where the stickiness depends on the surface soil abundance and roughness. No functional significance of the sculpture pattern could not be detected in this study.

• Journal of Plant Biology
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• v.27 no.3
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• pp.149-162
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• 1984

Anatomical characters of the secondary xylem in roots of Lauraceae, including 6 genera and 13 species grown in Korea, were studied systematically. Lauraceors members studied anatomically possess characters of the secondary xylem that are in the main more specialized than those found in the primitive angiosperm families. The specialized characters are as follows; (1) mostly solitary pores with some radially multiples, (2) mostly simple perforation plates and partially scalariform perforation plates in all species, (3) slightly oblique end wall of vessel element, (4) predominantly alternate intervascular pitting, (5) paratracheal axial parenchyma in all species, (6) heterogeneous II or III vascular rays. It is considered that the series of specialization in this family from the perforation plates and angle of end wall to the vessel axis is as follows; MachiluslongrightarrowNeolitsealongrightarrowLinderalongrightarrowCinammomumlongrightarrowIozostelongrightarrowLitsea.

• Korean Journal of Plant Taxonomy
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• v.48 no.1
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• pp.9-23
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• 2018

The distribution of orbicules was investigated for eleven taxa of six genera in Lamiaceae and four taxa of three genera in Verbenaceae using scanning electron microscopy. A literature survey to evaluate the phylogenetic potential of the orbicules and their possible correlations with tapetum types was also conducted. The orbicules are consistently absent in all investigated taxa of Lamiaceae, while small orbicules of an average size of less than $1{\mu}m$ are densely distributed in Verbenaceae. In fact, orbicules appear consistently in 123 of 150 angiosperm families when investigated in at least one species. Thus, the distribution patterns of orbicules could be a useful diagnostic character in angiosperms. In addition, orbicules occur in 84% taxa of the secretory tapetum type, while they are commonly absent in the amoeboid tapetum type (ca. 80%). The presence of orbicules may be correlated with the secretory tapetum type. However, the study of orbicules is restricted in 150 families and the tapetum type within these families can be applied for 92 families out of a total of 416 angiosperm families. Thus, further investigation of orbicules is necessary in extended taxa to address the questions pertaining to orbicules.

• Journal of the Korean Wood Science and Technology
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• v.12 no.1
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• pp.11-30
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• 1984

This study was executed to offer the basical data needed to the plywood industry as examining on the wood characteristics of veneer species that grow in Korea. According to the aggravation of log import from foreign countries caused by the gradual exhaustion of wood resources in recent years, the study on wood characteristics of veneer species growing in Korea should be carried out preferentially in promotion of the domestic timber utilization and development of it's processing technique for plywood industry. 50 commercial veneer species in this study were selected from 33 genuses, and general macroseopical wood characteristics for them were examined and described by the species. And also keys for the identification based on gross features were briefly prepared and presented by gymnosperm and angiosperm respectively.

• Korean Journal of Plant Taxonomy
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• v.38 no.3
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• pp.197-222
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• 2008

A recently published Korean Flora, "The genera of vascular plants of Korea (GFK)", includes the descriptions and keys for 217 families, 1,044 genera, and 3,209 species of Korean vascular plants. We reclassified these taxa according to the recent APG classification system, which resulted in 64 orders, 204 families, 1,044 genera and 3,209 species. Twenty-two families from the GFK were abandoned because of changes to the familial delimitations in the APG system. In contrast, the number of families in the Liliaceous group was increased. The Liliaceae in the GFK included 31 genera and 109 species. These taxa are now assigned to 10 families in four different orders including Liliales, Asparagales, Alismatales, and Dioscoreales because of the drastic changes to the monocot classification system in the past 20 years. In addition, the family name of the Aucubaceae was changed to Garryaceae. As a result, the number of families in the GFK has been reduced to 204. The results were summarized in four tables and two figures at the levels of unofficial higher taxonomic hierarchies, orders, families and genera. This new information can provide a guidelines for selecting the phylogenetic analysis unit for the Korean tree of life (KTOL) project. Futhermore, the updated classification system also provides an important summarization for the systematic community for placing the Korean flora in a modern phylogenetic context.

• Journal of Photoscience
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• v.9 no.2
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• pp.326-328
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• 2002

In many plant cells, the positions of chloroplasts change in response to changes in light conditions. In the epidermal cells of the aquatic angiosperm Vallisneria gigantea, the avoidance response of chloroplasts is induced specifically by irradiation with blue light of high intensity. Possible roles of actin cytoskeleton in the blue-light-induced avoidance response of chloroplasts were investigated by partial irradiation and phalloidin staining. We showed that the blue-light-dependent redistribution of chloroplasts was induced only in the limited area, where exposed to blue light, even in individual cells. In addition. in the exposed area, the configuration of actin filaments strikingly changed compared with that before the irradiation. Short and thick bundles of actin filaments surrounding the chloroplasts changed to much longer and thinner bundles with a more stretched array. In contrast, in the unexposed area, neither the distribution of chloroplasts nor the configuration of actin filaments exhibited any changes. Cytochalasin D and latrunculin B inhibited the avoidance response of chloroplasts concomitantly with the fragmentation of actin filaments. These results indicate that the reorganization of actin filaments plays a crucial role in the induction of avoidance response of chloroplasts.