1995 Fiscal Year Final Research Report Summary
Three-dimentional images of deposition of microfibrils and matrix substances in the cell wall
| Project/Area Number |
06404013
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
林産学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
SANO Yoshihiro Hokkaido Univ., Fac. of Agr., Pro., 農学部, 教授 (10001463)
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| Co-Investigator(Kenkyū-buntansha) |
KOJIMA Yasuo Hokkaido Univ., Fac. of Agr., Lecture, 農学部, 講師 (90161918)
URAKI Yasumitsu Hokkaido Univ., Fac. of Agr., Assist. Pro., 農学部, 助教授 (90193961)
SANO Yuzou Hokkaido Univ., Fac. of Agr., Assist. Pro., 農学部, 助手 (90226043)
FUNADA Ryo Hokkaido Univ., Fac. of Agr., Assist. Pro., 農学部, 助教授 (20192734)
OHTANI Jun Hokkaido Univ., Fac. of Agr., Pro., 農学部, 教授 (30001465)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Cellulose Microfibril / Cortical Microtubule / Confocal Laser Microscopy / FE-SEM / Cell wall / Matrix |
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| Research Abstract |
The arrangement of cortical microtubules (MTs) in differentiating tracheids of conifers was examined by confocal laser scanning microscopy after immunofluorescent staining. The arrays of MTs in the tracheids during formation of the primary wall were not well ordered and the predominant orientation changed from longitudinal to transverse. During formation of the secondary wall, the arrays of MTs were well ordered and their orientation changed progressively from a flat S-helix to a steep Z-helix and then to a flat S-helix as the differentiation of tracheids proceeded. The orientation of cellulose microfibrils (MFs) on the innermost surface of cell walls observed by FE-SEM changed in a similar manner to that of the MTs. The MFs changed their orientation, with clockwise rotation (viewed from the lumen side), from a flat S-helix to a steep Z-helix and then from a steep Z-helix to a flat S-helix during the formation of secondary wall. These results provide strong evidence for the co-alignment of MTs and MFs during the formation of the semi-helicoidal texture of the cell wall in conifer tracheids. No tracheids in which the MTs had been disassembled were observed in any radial series during the successive steps of differentiation. The orientation of MTs might change progressively without depolymerization of MTs, supporting the dynamic helical model. On the basis of our results, we propose a model for the orientation of MTs and MFs during the differentiation of tracheids.
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