Developmental and Structural Section
Huth, John K. , Cote, Gary G. .
Crystal-Producing Cells in Petioles of Deciduous Leaves.
Microscopic intracellular crystals of calcium oxalate are produced throughout the plant kingdom. It has often been proposed that these crystals defend against herbivory, but other roles have also been suggested, including the possibility that they sequester calcium from cell walls during controlled breakdown of plant tissues. One case of such controlled breakdown involving cell wall changes is the abscission of spent leaves and floral parts, in which a layer of cells with weakened cell walls is formed. Calcium oxalate crystals have been extensively studied in leaf blades of a large diversity of plants, but there have been only few reports of crystals in petioles. We collected abscised autumn leaves from 16 species of deciduous trees, and prepared cleared specimens of both leaves and petioles. Using brightfield and polarization microscopy, we examined the region adjacent to the abscission zone of the petioles for the presence of crystals. When crystals were found we documented their morphology and abundance. Species differed in the presence and shape of petiolar crystals. We are continuing this study by examining the petioles of young spring leaves and mature summer leaves of the same species. We will present a comparison of these results, and discuss a possible relationship with abscission.
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1 - Radford University, 501 Stockton Street, Radford, VA, 24142, USA
Presentation Type: Poster:Posters for Sections
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM