Minisymposium 16: Cell walls
Abs #
31004: Floral organ abscission and ectopic cell separation: insights into the interconnections between cells
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Presenter: |
Patterson, Sara E, spatters@wisc.edu |
Authors | Patterson, Sara E (A) Rao, Hongyu (A) Kusner, Karianne M (A) Rey, Camila (A) Robertson, Amber (A) Most, Ayala (A) | | Affiliations: |
(A): Department of Horticulture, University of Wisconsin, Madison
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| Web Site: | http://cmb.wisc.edu/profiles/PattersonSara.html | |
The dynamic nature of the interconnections between cells is fundamental to basic plant morphology and development. We have isolated two distinct types of mutants in Arabidopsis that are associated with these changes in the cell wall, thus regulating cell to cell adhesion or cell separation. One class of mutants we have designated as tfa (things fall apart) as the epidermal, cortical and vascular cells of the hypocotyls and cotyledon tissues slough off the developing seedling. This phenotype is conditional and the severity of expression is dependent on humidity and temperature. We have identified three independent ectopic cell separation mutants and determined that 2 of these (tfa1-1 and tfa1-2) are allelic, while the third (tfa2) is regulated by an independent gene. These mutants are most likely disruption of negative regulators of the cell separation process. Our second class of mutants, the dab mutants (delayed floral organ abscission) display retention of floral organs for an extended duration two to three times longer than wild type. Genetic characterization shows we have identified mutations in eight independent genes, and these genes are probably directly regulating cell separation. Physiological characterization indicates that the dab mutants display 4 unique profiles of abscission indicating disruption at different stages of the abscission process. These patterns correlate with structural features as determined by light microscopy, florescence microscopy and scanning electron microscopy. In addition, we have observed that gene expression for several abscission-associated genes is altered in mutant background.
We will present an overview of what is known concerning cell-cell adhesion and cell separation, and highlight some of the molecular, morphological, and physiological characteristics of these newly identified mutants.
