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Recognition of Woody Plant Tissues by Mistletoe Cells

槲寄生细胞对木本植物组织的识别

基本信息

批准号：
02806034
负责人：
AZUMA Jun-ichi
金额：
$ 1.09万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02806034/
关键词：
Mistletoe Cultured cells Recognition Woody plant cells Recognition mechanism 相互認識機構

项目摘要

In order to clarify interactions between mistletoe and its host cell, both plants were converted into a tissue culture system. A mistletoe (Viscum Album L.) and its host, huckberry wood (Celtis sinensis P.), were successfully cultured in vitro in Murashige-Skoog medium containing a half of the ionic strength of the original medium and supplemented with 1.0 ppm of 1-naphthaleneacetic acid and 0.1 ppm of benzyladenine at 28ﾟC under 12-hr day length at about 2, 500 lux. When a seed of mistletoe was planted on the host callus cells, a root of mistletoe grew out and began to contact with host cells. Both tissues were found to grow without contac inhibition, indicating development of a in vitro system of parasitism. The present results are expected to be useful for further characterization of plant cell-cell recongnition in molecular order level.Nextly, properties of a substance which was indispensable at the initial stage of parasitism was characterized. A sticky material which was necessary to attach the seed of mistletoe on the branch of its host for a long time enough to insert its root into the host tissue was isolated from fruits of mistletoe and named as viscan because of its viscous property. Viscan was kind of complex composed of 66% cellulose and 34% hemicellulose. X-ray diffraction analysis showed that viscan was amorphous but turned into a typical cellulose II polymorph after alkaline treatment. Atomic force microscopy revealed that the polysaccharide was fibrous having a mean diameter of 1.7nm. Solid state NMR spectroscopic analysis confirmed that the lyophilized viscan had nature of a mixture of low crystalline cellulose and amorphous hemicellulose. Based on the present results, mistletoe was concluded to use a v iscous cellulose-hemicellulose complex as natural adhesive at an initial stage of parasitism.

为了阐明槲寄生与其宿主细胞之间的相互作用，将两种植物转化为组织培养系统。槲寄生（Viscum Album L.）及其寄主朴树（Celtis sinensis P.）成功地在Murashige-Skoog培养基中体外培养，该培养基含有原始培养基一半的离子强度，并补充有1.0ppm的1-萘乙酸和0.1ppm的苄基腺嘌呤，培养温度为28 ℃，光照时间为12小时，照度约为2500勒克斯。当槲寄生的种子种植在宿主愈伤组织细胞上时，槲寄生的根生长出来并开始与宿主细胞接触。这两种组织被发现生长无抑制，表明在体外寄生系统的发展。这些结果为进一步从分子水平上研究植物细胞间的相互作用提供了理论依据。从槲寄生果实中分离出一种粘性物质，这种物质是槲寄生种子长时间附着在其宿主的分支上以使其根插入宿主组织所必需的，并因其粘性而被命名为viscan。Viscan是由66%的纤维素和34%的半纤维素组成的复合物。X射线衍射分析表明，viscan是无定形的，但变成一个典型的纤维素II多晶型物后，碱处理。原子力显微镜观察表明，该多糖为纤维状，平均直径为1.7nm。固态NMR光谱分析证实，冻干viscan具有低结晶纤维素和无定形半纤维素的混合物的性质。根据目前的研究结果，槲寄生的结论是使用粘性纤维素-半纤维素复合物作为天然粘合剂在寄生的初始阶段。