Cytoskeleton Structure and Dynamics
Honig, Arik , Miller, Gad , Abu Abied, Muhamad , Sadot, Einat , Zilberstein, Aviah .
Characterization of the Structure and Function of Arabidopsis thaliana Cell Wall Linker Protein (CWLP).
Proline (Pro) is the most common osmolyte accumulated in plants in response to diverse osmotic stresses, accompanied by a concomitant increase in the level of certain Proline Rich Proteins (PRPs). The Arabidopsis thaliana Cell Wall Linker Protein (AtCWLP), which is a proline rich protein, has been chosen as a model for estimating the role of PRPs in stress tolerance and the need for available free proline for their accumulation. AtCWLP predicted structure includes an N-terminal proline rich external domain anchored to the cell wall (CW), three transmembrane domains and a cytoplasmic protruding C-terminal end. Plants overexpressing the CWLP::GFP translational fusion were generated and characterized. Immunolocalization and co-staining with a membrane-specific dye revealed that CWLP::GFP is assembled in small clusters scattered along the plasma membrane (PM). Dehydration experiments showed that the CWLP overexpressing (CWLP-OE) and CWLP::GFP plants are more tolerant than WT plants to water shortage. Moreover, higher levels of CWLP::GFP are assembled in the PM when Pro is being accumulated. Plasmolysis experiments with detached leaves confirmed that the CWLP-O.E and CWLP::GFP leaves are more tolerant to water loss. Confocal LSM observations revealed that while leaf cells of the CWLP-OE or CWLP::GFP plants could maintain normal cytoskeleton structure and did not show protoplast shrinkage during plasmolysis, the WT cells revealed protoplast contraction and destruction of microtubule structure. These results suggest that the high abundance of CWLP molecules strengthens the physical connection between the PM and the cell wall and also directly or indirectly affects the cytoskeleton structure. We are currently characterizing the CWLP cellular functions using fluorescently-tagged cytoskeleton components expressed either in CWLP-OE or cwlp plants.
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1 - Tel Aviv University, Plant Sciences
2 - The Volcani Center, Bet dagan, Ornamental Horticulture
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM