Date of Award

Spring 2004

Document Type



Life & Environmental Sciences

First Advisor

Sam Alvey

Second Advisor

Marilyn Schendel

Third Advisor

Linda MacCammon


Abscission, an active process resulting in the removal of an organ from the main body of a plant, occurs naturally in response to pathogens, disease, or when the plant part is no longer needed. Several delayed abscission mutants have been identified from the University of Wisconsin T-DNA tagged mutant populations in Arabidopsis thaliana. One of the identified mutants, dab5-l, is characterized by a delay in abscission causing the floral organs to remain attached past position ten; however, all other plant functions are normal. DAB5 has been thought to be involved in the secretory pathway. The present study was conducted to further characterize DAB5 expression at the cellular, tissue, and organelle levels using reporter gene constructs, light microscopy, scanning electron microscopy, and RT PCR. DAB5 expression was found in the roots, root tips, cotyledons, meristem, abscission zone, and anthers. However, no DAB5 expression was present in the hypocotyl.