Poster: Secondary metabolism

Abs # 273: The isolation of BEBT from Petunia hybrida: a flower specific gene involved in floral volatile synthesis

Presenter:	Dexter, Richard J., rdexter@ufl.edu
Authors	Dexter, Richard J. (A)   Shibuya, Kenichi  (A)   Underwood, Beverly A. (C)   Loucas, Holly M. (A)   Tieman, Denise M. (B)   Klee, Harry J. (B)   Clark, David G. (A)
Affiliations:	(A): Department of Environmental Horticulture, University of Florida, Gainesville, FL (B): Department of Horticulture, University of Florida, Gainesville, FL (C): The Institute for Genomic Research, Rockville, MD
Web Site:	http://hort.ifas.ufl.edu/floriculture/floriculture_bio.htm

Petunia hybrida cDNA microarray analysis was utilized to isolate flower petal specific genes. One clone was isolated that showed homology to benzyl-coenzyme A:benzyl alcohol benzoyl transferase (BEBT) which was previously characterized in Clarkia breweri (Auria et al. 2002). BEBT catalyzes the conversion of benzyl alcohol to benzylbenzoate but also has activity with a number of other alcohols including cinnamyl alcohol and 2-phenyl ethanol. Spatial analysis of mRNA expression showed that this gene, PhBEBT1, was predominately expressed in the corolla. To confirm the function of the putative petunia BEBT, we produced transgenic RNAi plants with reduced expression of PhBEBT1. Floral volatile emission analysis of these plants using gas chromatography confirmed decreased emission of benzylbenzoate along with a corresponding decrease in corolla mRNA levels. Additionally, an increase in emission of the direct precursor, benzyl alcohol, was observed in BEBT-RNAi flowers. Expression of PhBEBT1 mRNA and benzylbenzoate emission with respect to ethylene-regulated floral senescence will be discussed.