Poster: Cell Walls

Abs # 1269: Cell biology of secondary cell wall development in Arabidopsis

Presenter:	Kaneda, Minako , minako@interchange.ubc.ca
Authors	Kaneda, Minako  (A)   Rensing, Kim  (A)   Samuels, Lacey  (A)
Affiliations:	(A): University of British Columbia

Lignin, a complex phenolic polymer, is important for mechanical support, water transport, and defence in vascular plants. The lignin biosynthesis pathway called phenylpropanoid metabolism has been inferred but little is known about the mechanisms of monolignol export and its incorporation into lignin in the lignifying tissues of plants. �@�@In cell structure studies of developing secondary xylem (wood) in pine, novel Golgi structures such as branching trans-Golgi networks and clusters of dark staining vesicles indicated that lignification may involve Golgi-mediated secretion (Samuels et al. 2002 Planta). We believe that angiosperms also require Golgi-mediated secretion for formation of the secondary cell wall. We are using Arabidopsis as a model of secondary cell wall development for comparison to the angiosperm tree, poplar. The cell structure of developing xylem is being tracked using high quality techniques such as high-pressure freezing and freeze substitution for observation of the cell organelles such as Golgi network, ER and cell membranes. In addition, we hope that light and electron microscopic autoradiography, using the lignin precursor, 3H-L-phenylalanine, will give us a better understanding about the movement of monolignols through the cell.