1991 Fiscal Year Final Research Report Summary
Recognition of Woody Plant Tissues by Mistletoe Cells
| Project/Area Number |
02806034
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
林産学
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| Research Institution | Kyoto University |
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Principal Investigator |
AZUMA Jun-ichi Kyoto University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (80115782)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMURA Keizo Kyoto University, Faculty of Agriculture, Professor, 穣学部, 教授 (50026506)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Mistletoe / Cultured cells / Recognition / Woody plant cells / Recognition mechanism |
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| Research Abstract |
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.
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