<i>Pinus taeda</i> L. suspension culture cells were used to develop a model system to study the process of lignification occurring during the early stages of cell wall formation and maturation. Chemical, biochemical and histochemical analyses of the <i>P. taeda</i> suspension cultures grown with 2,4-dichlorophenoxyacetic acid (2,4-D) as the growth regulator did not provide conclusive evidence for lignin deposition. On the other hand, cultures in which 2,4-D was substituted with α-naphthaleneacetic acid (NAA) were shown to lignify. During this induction of lignification, limited cell wall thickening occurred since transmission electron microscopy of the 2,4-D grown cells showed only primary walls while the average cell wall thickness of the NAA-grown cells was consistent with secondary (S₁) layer formation. Despite the possibility of only limited lignin deposition in the 2,4-0 grown cells, secondary metabolism had occurred as evidenced by reversed-phase and chiral chromatographic separations which revealed the ability of these cells to produce enantiomerically pure (-)-matairesinol. Administrations of [1-¹³C], [2-¹³C ] and [3-¹³C ] specifically labeled phenylalanines to the <i>P. taeda</i> suspension cultures in medium containing NAA allowed the determination of lignin bonding patterns <i>in situ</i> by solid-state ¹³C NMR spectroscopy of the resulting ¹³C enriched cells.
Aqueous and organic solvent extractions and protease treatment yielded ¹³C enriched cell walls for solid-state ¹³C NMR spectroscopic analyses of the cell wall bound lignin component. Subsequently, an isolated lignin derivative from these cell walls was analyzed by solution-state ¹³C NMR spectroscopy and verified the assignments made in the solid-state. Accordingly, the above experiments represent the first demonstration of lignin bonding patterns <i>in situ</i> in a <i>Pinus</i> species as well as a suspension culture. This culture system possesses great potential as a model to thoroughly study the early stages of lignification. / Ph. D.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/38851 |
| Date | 28 July 2008 |
| Creators | Eberhardt, Thomas Leonard |
| Contributors | Wood Science and Forest Products, Lewis, Norman G., Ifju, Geza, Cramer, Carole L., Glasser, Wolfgang G., Hess, John L., White, Robert H. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Dissertation, Text |
| Format | x, 191 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 26064283, LD5655.V856_1992.E237.pdf |
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