Poster: Vegetative Development

Abs # 435: Evidence for the regulation of two independent programmed cell death pathways in Arabidopsis thaliana by the At-Dad1 gene

Presenter:	Calderon-Urrea, Alejandro , calalea@csufresno.edu
Authors	Calderon-Urrea, Alejandro  (A)   Suárez-Rodríguez, MariaCristina  (B)   Polack, Glenda W (A)
Affiliations:	(A): California State University, Fresno (B): University of Wisconsin-Madison
Web Site:	http://zimmer.csufresno.edu/~calalea/

Programmed cell death (PCD) is a genetically regulated process in which cells activate their own death. In plants, PCD takes place during development in such processes as senescence, flower development, and in response to pathogen infection. Among PCD genes identified in animals, two share sequence similarities with plant genes: the Dad1 gene (defender against cell death) and the BI l-gene (bax-like inhibitor). In this study, the pattern of expression of the Dad1-like gene of Arabidopsis thaliana (At-Dad1) was analyzed by mRNA in situ hybridization in an attempt to determine its role in normal cell death in plants. Intense signal was observed in young tissues fated to undergo PCD with a subsequent reduction of the signal at the onset of cell death, supporting the idea that At-Dad1 functions as a plant cell death regulator. Furthermore, we show that even though At-Dad1 regulate cell death of tracheary cells, papillae cells, and tapetum cells only tapetum cells do not show the TUNEL staining during cell death characteristic of tracheary and papillae cells.