Poster: Late and Moved Abstracts

Abs # 1386: Functional analysis of the FIDDLEHEAD gene family

Presenter:	Dominguez, Eva M, dominguez@purdue.edu
Authors	Dominguez, Eva M (A)   Lolle, Susan J (A)   Pruitt, Robert E (A)
Affiliations:	(A): Purdue University

The FIDDLEHEAD (FDH) gene is involved in epidermal cell interactions, blocking organ fusion at early stages of development as well as pollen growth on leaf surfaces. Previous biochemical analyses indicate that this gene may be involved in lipid synthesis of the cuticle and shows similarity to beta ketoacyl synthases. A blast search in the Arabidopsis genome has identified 20 genes with protein similarity to FDH. In order to study the biochemical function of this gene family a series of translational fusions between FDH and members of the family has been done. We have already identified one gene, FIDDLEHEAD LIKE 1, that can functionally substitute for FDH when expressed in the same temporal and spatial pattern. A series of gene chimeras with different portions of FDH and two less closely related genes of the family will allow us to identify domains of the FDH protein that are either critical for FDH activity and/or can be replaced by the corresponding sequence from the related gene without eliminating the activity. Translational fusion of the green fluorescent protein (GFP) to FDH driven by the native promoter has localized the protein to the outermost part of the epidermal cell wall of aerial tissues, being absent in root epidermal walls. This expression is consistent with the postulated role for FDH in cuticle-cell wall biosynthesis. Furthermore, a series of N terminal and C terminal deletions of Fdh fused to GFP has let us identify which part of the FDH protein is responsible for the cell wall targeting.