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Cellulose structure and lignin distribution in normal and compression wood of the Maidenhair tree(Ginkgo biloba L.)

Journal of Integrative Plant Biology 2015年第4期57卷 388-395页

作者： Seppo Andersson Yurong Wang Raili P?nni Tuomas H?nninen Marko Mononen Haiqing Ren Ritva Serimaa Pekka Saranp?? Department of Physics University of Helsinki Research Institute of wood Industry Chinese Academy of Forestry Department of Forest Products Technology Aalto UniversitySchool of Chemical Technology VTT Technical Research Centre of Finland Natural Resources Institute Finland

We studied in detail the mean micro fibril angle and the width of cellulose crystals from the pith to the bark of a 15-year-old Maidenhair tree（Ginkgo biloba L.）. The orientation of cellulose micro fibrils with respect to the cell axis and the width and length of cellulose crystallites were determined using Xray diffraction. Raman microscopy was used to compare the lignin distribution in the cell wall of normal/opposite and compression wood, which was found near the pith. Ginkgo biloba showed a relatively large mean micro fibril angle,varying between 19° and 39° in the S2 layer, and the average width of cellulose crystallites was 3.1–3.2 nm. Mild compression wood without any intercellular spaces or helical cavities was observed near the pith. Slit-like bordered pit openings and a heavily lignified S2 L layer con firmed the presence of compression wood. Ginkgo biloba showed typical features present in the juvenile wood of conifers. The micro fibril angle remained large over the 14 annual rings. The entire stem disc,with a diameter of 18 cm, was considered to consist of juvenile wood. The properties of juvenile and compression wood as well as the cellulose orientation and crystalline width indicate that the wood formation of G. biloba is similar to that of modern conifers.

关键词： Cellulose structure cell wall compression wood lignin Maidenhair tree microfibril angle

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Common Mechanism of Lignification of compression wood in Conifers and Buxus

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American Journal of Plant Sciences 2016年第7期7卷 1151-1162页

作者： Hideto Hiraide Masato Yoshida Saori Sato Hiroyuki Yamamoto Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan

woody plants develop a specialized secondary xylem known as reaction wood to enable formation of an ideal shape. Reaction wood in coniferous species is known as compression wood, and that of woody angiosperms as tension wood. However, the genus Buxus which is classified as an angiosperm, forms compression-wood-like reaction wood. We investigated the mechanism of lignification in coniferous compression wood and Buxus reaction wood: 1) Several lignin synthesis genes were upregulated in differentiating reaction wood of Buxus microphylla;2) B. microphylla possesses a specific laccase gene that is expressed specifically in differentiating reaction wood (BmLac4);3) laccase activity localization was closely related to lignification of reaction wood, and laccase activity was high in the secondary wall middle layer;4) in reaction wood cell walls, galactan was present in the outer portion of the secondary wall middle layer, and the level of xylan was reduced. These findings suggest that lignification in B. microphylla reaction wood is identical to that of coniferous compression wood. These may represent general mechanisms of increasing lignin content in various reaction woods.

关键词： Lignification Laccase Buxus Reaction wood compression wood

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派阳山林场从事业型林场向企业型林场转变的调查

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中国农村经济 1995年第7期 54-56页

作者：李甫春韦尊达秦崇彪广西国营派阳山林场广西社会科学院

派阳山林场从事业型林场向企业型林场转变的调查李甫春，韦尊达，秦崇彪长期在计划经济体制下专司营林的国家林场，如何向社会主义市场经济体制转轨，从按计划营林向按市场需求经营过渡，从事业型林场向企业型林场转变，最终按市场经济... 详细信息

派阳山林场从事业型林场向企业型林场转变的调查李甫春，韦尊达，秦崇彪长期在计划经济体制下专司营林的国家林场，如何向社会主义市场经济体制转轨，从按计划营林向按市场需求经营过渡，从事业型林场向企业型林场转变，最终按市场经济体制运转？广西国营派阳山林场经过几...

关键词： Masson pine Branchwood compression wood Opposite wood Chemical properties Physical and mechanical properties

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An Overview of the Biology of Reaction wood Formation

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Journal of Integrative Plant Biology 2007年第2期49卷 131-143页

作者： Sheng Du Fukuju Yamamoto Faculty of Agriculture Tottori University Minami 4-101 Koyama Tottori 680-8553 Japan

Reaction wood possesses altered properties and performs the function of regulating a tree＇s form, but it is a serious defect in wood utility. Trees usually develop reaction wood in response to a gravistimulus. Reaction wood in gymnosperms is referred to as compression wood and develops on the lower side of leaning stems or branches. In arboreal, dicotyledonous angiosperms, however, it is called tension wood and is formed on the upper side of the leaning. Exploring the biology of reaction wood formation is of great value for the understanding of the wood differentiation mechanisms, cambial activity, gravitropism, and the systematics and evolution of plants. After giving an outline of the variety of wood and properties of reaction wood, this review lays emphasis on various stimuli for reaction wood induction and the extensive studies carried out so far on the roles of plant hormones in reaction wood formation. Inconsistent results have been reported for the effects of plant hormones. Both auxin and ethylene regulate the formation of compression wood in gymnosperms. However, the role of ethylene may be indirect as exogenous ethylene cannot induce compression wood formation. Tension wood formation is mainly regulated by auxin and gibberellin. Interactions among hormones and other substances may play important parts in the regulation of reaction wood formation.

关键词： auxin cambial growth compression wood ethylene gibberellin gravitropism indoleacetic acid plant hormone reaction wood tension wood.

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