Growth and Vegetative Development
Dickerson, Tiffany J , Hoffmann-Benning, Susanne .
Characterization of proteins from corn coleoptile epidermis that are involved in auxin-induced growth.
Rapidly growing corn coleoptiles display a phenomenon called “tissue tension”. When they are cut longitudinally, they curve outwards with the epidermis on the concave side of the section. Tissue tension has been interpreted as the manifestation of two conflicting forces: the epidermis is under tension because it is growth limiting, while the inner tissue does not limit growth and is under compression. During examination of the cell ultrastructure of rapidly growing plants, osmiophilic particles (OPs) had been observed in several plant species. These particles are 80-300nm in diameter. Electron microscopy and labeling experiments had shown that they are closely associated with the outer epidermis of growing tissues, are going through the secretory pathway, and are, at least in part, proteinaceous. From their location and time of appearance we can assume that they are related to either cell-wall or cuticle biosynthesis. As precursors of the plant cuticle, they would be essential in multiple ways: in addition to playing a role in plant growth, they may be important in the defense against pathogens and in the prevention of water loss. We used a proteomics approach to try to identify novel proteins involved in regulating plant growth via cell wall or cuticle biosynthesis by comparing the protein profile of slow versus rapidly growing coleoptile and coleoptile epidermis. We were able to identify over 80 proteins that appear to be induced in rapidly growing coleoptile epidermis. Half of those are related to protein synthesis/maintenance and 11% are potentially associated with the cell wall, cuticle, or lipid metabolism. We are now analyzing the expression and distribution of the latter proteins plus an additional three hypothetical proteins with unknown function.
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1 - Michigan State University, Department of Biochemistry and Molecular Biology, 120 Biochemistry Building, East Lansing, MI, 48824, USA
2 - Michigan State University, Department of Biochemistry and Molecular Biology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM