• Title/Summary/Keyword: Leaf anatomy

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Molecular phylogeny and divergence of photosynthetic pathways of Korean Cypereae (Cyperaceae) (한국산 방동사니족(사초과) 식물의 분자계통과 광합성경로의 분화)

  • Jung, Jongduk;Ryu, Youngil;Choi, Hong-Keun
    • Korean Journal of Plant Taxonomy
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    • v.46 no.3
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    • pp.314-325
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    • 2016
  • Multiple changes of the photosynthesis pathway are independent evolutionary events occurring in the phylogeny of flowering plants, and such changes have occurred more than five times in Cyperaceae. In the tribe Cypereae, the C4 photosynthetic pathway appeared only once and is regarded as a synapomorphy of the C4 plants within this tribe. The morphological delimitation of genera within Cypereae does not correspond to their molecular phylogenetic relationships. In this study, the molecular phylogeny was compared with the photosynthetic pathways of Korean Cypereae (18 species of Cyperus, 1 species of Kyllinga, and 1 species of Lipocarpha). The photosynthetic pathways were determined by observing the leaf anatomy. The phylogenetic analysis was performed using three DNA regions (nrITS, rbcL, and trnL-F). According to the position of the photosynthetic tissue, 4 species (C. difformis, C. flaccidus, C. haspan, and C. tenuispica) and 16 species (14 Cyperus species, K. brevifolia var. leiolepis, and L. microcephala) were confirmed as C3 and C4 plants, respectively. Tribe Cypereae was divided into the CYPERUS and FICINIA clades, and all species of Korean Cypereae plants belonged to the CYPERUS clade in the phylogenetic analysis. Within the CYPERUS clade, C4 plants were monophyletic but their phylogenetic relationships were unclear. The genera Kyllinga and Lipocarpha were not supported as an independent genus in either case because they were nested by the Cyperus species in the molecular phylogenetic trees in the present and in previous studies. To determine the classification within the CYPERUS clade, a detailed morphological study and a molecular phylogenetic analysis at a high resolution will be necessary.

Expression of Laminin in Rat Tracheal Mucosa after Exposure to Sulfur Dioxide Gas (Sulfur Dioxide 가스 흡입 후 흰쥐 기관 점막에서 Laminin의 발현에 대한 연구)

  • Lee, Hyung-Seok;Yu, Yean-Hee;Cho, Seok-Hyun;Kim, Kyung-Rae;Chung, Ho-Sam
    • Korean Journal of Bronchoesophagology
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    • v.6 no.1
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    • pp.29-37
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    • 2000
  • Background and Objectives : The concentration of sulfur dioxide($SO_2$) gas in the ambient air appears increasing in the industry and urban area day by day. It was known that $SO_2$ is noxious gas. $SO_2$ can be irritating to the eyes, nose, throat, upper respiratory tract and skin. It produces sulfurous acid on contact with water and is extremely irritating to the nasopharynx and respiratory tract. Laminin is a family of extracellular matrix glycoproteins localized in the basement membrane that separates epithelial cells from the underlying stroma. The biological activities of laminin are to promote cell migration, wound healing, growth and differentiation. Meterials and Methods : The histologic changes and the expression of laminin in tracheal mucosa sacrificed at every weeks (to 7 weeks) after continued $SO_2$ exposure of 250ppm for 30 minutes a day were studied in rats. Results : Pathologic tissue was formed at the tracheal mucosa and the underlying tissue by the infiltration of monocytes and epithelium was transformed to the single cell layered epithelium above 5 weeks after exposure. At the 6 weeks after exposure, epithelial cells were partially lost and epithelial cell layer was transformed to be leaf-shaped. Submucosal tissue was transformed to be lymphatic tissue. An intense positive staining for laminin was found in apical cytoplasm and lateral surface of the normal epithelial cells and basement membrane but at the 5 and 6 weeks after exposure, laminin activity was decreased to the moderate activity. At the 7 weeks after exposure, laminin activity was decreased to the weak activity. Conclusion : Our finding suggests that $SO_2$ makes histologic damage on the tracheal mucosa and decreases immunoreactivity for laminin. Longer duration of the exposure of $SO_2$ makes more histologic damage on the tracheal mucosa and decreases immunoreactivity for laminin.

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