Poster: Signaling, cell-to-cell

Abs # 445: Expression and cellular localization of dab 5-1, a delayed abscission mutant, in Arabidopsis thaliana.

Presenter:	Patterson, Sara E., spatters@facstaff.wisc.edu
Authors	Patterson, Sara E. (A)   Rao, Hongyu  (A)   Robertson, Amber  (B)   Kusner, Karianne  (A)
Affiliations:	(A): Department of Horticulture, University Of Wisconsin (B): Carroll College, Helena, Montana

Abscission is a specialized cell separation process that results in shedding of organ systems such as leaves, petals and fruits. This process is developmentally regulated, and also occurs in response to pathogens, disease or other environmental signals. Several delayed floral organ abscission mutants have been identified from the University of Wisconsin T-DNA tagged mutant populations in Arabidopsis thaliana. One of these mutants, dab 5-1, is characterized by a delay in abscission resulting in the floral organs remaining attached significantly longer. In dab5-1 the cells of the abscission zone are weakened and display irregular and uncontrolled elongation. All other plant functions observed appear normal. We have cloned DAB5 and it is homologous to mammalian genes that are involved in the secretory pathway. We will present phenotypic and physiological characterization of dab 5-1 using light microscopy, scanning electron microscopy, and breakstrength analysis. We will also present DAB5 expression at the cellular, tissue, and organelle levels using reporter gene constructs and RT PCR. Early abscission can lead to loss in yield and quality and we believe that understanding genes such as DAB5 will ultimately lead to crop improvement. This work was funded by USDA grant 0035301-9085