• 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.

• Journal of Pharmacopuncture
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• v.5 no.1 s.8
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• pp.159-169
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• 2002

Objective: It will be examined in this research whether Lacquer poison can be used as an distinguished treatment to cure incurable diseases by considering literature existing and various papers. Method: I studies origin, alias, species, toxicity, effect, treatment, component, medical action and contraindication of Rhus vemiciflua stokes through various kinds literatures. Results: Sap of Rhus vemiciflua stokes that is used for medical purposes, has an effect on anti-tumor, anti-oxidation, hangover cure, and gastritis suppression. Even though urushiol and fIavonoids, the main ingredient of lacquer, has medical cure effects. but urushiol results in a dermatropic allergy. Sincc xylem of a Rhus vemiciflua stokes, however. does not induce the allergy but has medical efficacy, research on this topic is needed.

• Journal of the Korean Wood Science and Technology
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• v.15 no.4
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• pp.1-11
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• 1987

한국산(韓國産) 활엽수재(潤葉樹材) 27과(科) 45속(屬) 82종(種)을 선정(選定)하여 이들 목부(木部)에 존재(存在)하는 결정(結晶)의 형태(形態) 및 분포(分布)를 조사(調査)함으로써 얻은 결과(結果)를 간단히 요약(要約)하면 다음과 같다. 1. 다면체형(多面體形)의 결정(結晶)이 가장 많이 관찰(觀察)되었으며 집정(集晶)도 종종 관찰(觀察)되었으나 주정(柱晶)은 극히 일부 수종(樹種)에서만 나타났다. 2. 이러한 결정(結晶)은 주로 축방향유조직(軸方向柔組織) 및 방사조직(放射組織)에 존재(存在)하였으며 수(髓), 타일로시스, 진정목섬유(眞正木纖維) 및 수반점(髓斑點)에서도 그 존재(存在)가 확인(確認)되었다. 3. 대부분의 결정세포(結晶細布)는 재분제(再分製) 및 확대(擴大)를 통하여 변형(變形)되므로써 결정(結晶)을 지니지 않은 세포(細胞)와 그 형태적(形態的)인 차이를 나타내었다.

• Journal of Plant Biotechnology
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• v.3 no.3
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• pp.131-134
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• 2001

In $\lambda$-Zap II vector system, a cDNA library was constructed for the developing secondary xylem mRNA from hybrid poplar, Populus nigra x maximowiczii. A cDNA clone of 1.5 kb in size, pOMTB1.4 encoding a lignin-bispecific O-methyltransferase was screened by plaque hybridization using a probe of 540 bp cDNA amplified by polymerase chain reaction from the cDNA library and identified by nucleotide sequencing. Its nucleotide sequence contains one open reading frame of 366 amino acids. The deduced amino acid sequence in comparison with that of Populus tremuloides showed the differences of 9 amino acids and revealed 85-99% homology among alfalfa, poplar and aspen.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.103-108
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• 1991

The chemical characteristics of lignin in the differentiating xylem were investigated and compared with those of mature-wood. The compound middle lamella lignin deposited in the early stage of lignification of cell walls in the softwood(Larch) as well as the hardwood(Birch) was confirmed to be the so-called guaiacyl-type lignin and was found to have a relatively larger content of phenoxy hydroxyl group as terminal units and to be more abundant in condensed-type structures like as phenylcoumaran structures compared with mature-wood lingin.

• YAKHAK HOEJI
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• v.6 no.1
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• pp.21-24
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• 1962

A report is given of microscopic study of the root Angelica gigas Nakai comparing with Ligusticum acutilobum S. et Z.(=Angelica acutiloba Kitagawa). The following characteristics are outstanding. 1. Angelica gigas Nakai is more tender and softer than Ligusticum acutilobum S. et Z. 2. Both Angelica gigas Nakai and Ligusticum acutilobum S. et Z. are alike in the form and arrangement of fundamental parenchyma in cortex and xylem. 3. No mechanical tissues are present but the substitute fibers in the Angelica gigas Nakai and Ligusticum acutilobum S. et Z. 4. The intercellular space are more numerous and larger in Angelica gigas Nakai than in Ligusticum acutilobum S. et Z. 5. Secretory tissue in Angelica gigas Nakai consists of numerous canals while in Ligusticum acutilobum S. et Z. very few.

• Korean Journal of Plant Resources
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• v.10 no.3
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• pp.271-273
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• 1997

This study was carried out to obtain basic envirinmental information of the native area and growth characteristics at different age of Dendropanax morbifera LEV. In the southern Korea. The Dendropanax morbifera LEV. Was grown naturally at Wando, Cheju(Mt. Halla), Yecheon(Kermoon island),Sinan(Hong isand), Jindo(Mt. Chermchill) and Haenam(Mt. Taeroon), all between 30 to 450m above the sea level. The soil characterisitics of the native area had a pH of 5.3 to 5.4 with 8.4 to 9.8% content of organic matter and 18.2 to 21.3% soil moisture. Flowering starting in the middle of July begun when the trees were 6 years old. Six year old trees are 129 cm in stem height, 34 mm in stem diameter,15.4 in number of leaves with petioles 12.9 cm long. Xylem sap can be obtained from over 10 year old trees that grew well and have over 10 cm stems in diameter.

• Journal of Plant Biology
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• v.34 no.4
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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.

• Applied Microscopy
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• v.17 no.1
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• pp.161-168
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• 1987

The elongated filamentous haustorial cells, hyphae, of Cuscuta australis R. Brown penetrated into the vascular tissues of the host plant Trifolium repens L. were studied by the light and electron microscopes. The hyphae reached the host xylem were invaded into the host vessels and then they grew within the host vessels. Finally these hyphae were differentiated into the water conducting elements, xylary hyphae, by thickening of the secondary walls. The hyphae reached the host phloem were branched at the apical regions. These hyphae possessed thin-layered cytoplasm involving the typical features of sieve elements such as the parallel arrays of smooth endoplasmic reticulum, plastids with the clusters of fine starch granules, and mitochondria with the dilated cristae. It was indicated that these hyphae were differentiated into the nutrients conducting elements, phloic hyphae. The structures described were compared with those of other parasitic plants and were discussed in view of the translocation of materials from host to parasite.