1996 Fiscal Year Final Research Report Summary
Analysis of cell wall construction processes using transgenic plants
| Project/Area Number |
07454220
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
植物生理
|
|---|
| Research Institution | Kagoshima University |
|---|
Principal Investigator |
NISHITANI Kazuhiko Kagoshima University, College of Liberal Arts, Associate professor, 教養部, 助教授 (60164555)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OKAMOTO Shigehisa Kagoshima University, College of Liberal Arts, Lecturer, 教養部, 講師 (30211808)
|
|---|
| Project Period (FY) |
1995 – 1996
|
| Keywords | endoxyloglucan transferase / tobacco BY-2 / Arabidopsis / xyloglucan / cell wall / transformant / XRP |
|---|
| Research Abstract |
The plant cell wall play a central role in morphogenesis as well as responsiveness to environmental signals. Xyloglucans are the principal component of the plant cell wall matrix, and serve as cross-links between cellulose microfibrils to form cellulosexyloglucan framework. Endoxyloglucan transferase (EXGT), which we isolated and characterized 1992, is an enzyme that mediates molecular grafting reaction between xyloglucan molecules. Although structural studies on cDNAs encoding EXGTs strongly suggest their important roles in construction of cell wall architecture, their physiological roles are still unknown. In this research project, we isolated EXGT proteins and genes, and analyzed their mode of enzyme action and expression profiles using transgenic Arabidopsis plants and tobacco BY-2 cells. Promoter / GUS fusion gene analysis for Arabidopsis EXGT-A1 gene has shown that this gene was expressed in all organs, and was preferentially expressed in cells where secondary cell wall was extensively deposited. Isolation of Arabidopsis cDNAs encoding proteins structurally related EXGT-A1 shows the presence of a fairly large multi-gene family of xyloglucan related proteins (XRP). Data suggested that different XRP genes may exhibit potentially different expression profiles with respect to tissue specificity and responsiveness to hormonal and mechanical signals. A tobacco EXGT-N1 protein exhibited both hydrolase and transferase activity toward xyloglucans. These results strongly suggest that each XRP functions either as hydrolase or transferase acting on xyloglucans, and share roles in cell wall construction and modification in different cells and tissues.
|
