Poster: Photomorphogenesis

Abs # 389: Functional analysis of the Arabidopsis FRS gene family in light signaling

Presenter:	Lin, Rongcheng , rl239@cornell.edu
Authors	Lin, Rongcheng  (A)   Yang, Jianping  (A)   Wang, Haiyang  (A)
Affiliations:	(A): Boyce Thompson Institute

FHY3 and FAR1 are two homologous proteins essential for phytochrome A controlled far-red responses in Arabidopsis. There are twelve additional FHY3/FAR1-related genes (named FRS, for FAR1-related sequences) in the Arabidopsis genome. This family of proteins is evolutionarily conserved, but appears to be plant-specific. Their amino acid sequence similarity and conserved secondary structure (most FRS proteins contain 1-3 coiled-coil domains and a putative nuclear localization signal), suggesting that this family of proteins might function as signal transducers regulating distinct light responses. To understand their roles in Arabidopsis photomorphogenesis, we first assessed their gene expression patterns at different developmental stages and growth conditions using RT-PCR and gene specific promoter::GUS fusions, and determined their protein subcellular localizations by visualizing translational fusions with green fluorescent protein (GFP). Secondly, we are generating both loss-of-function (RNAi and knockout mutants) and gain-of-function mutants (via constitutive overexpression) for each of the FRS gene family members. In addition, we are generating various double and higher order mutant combinations to overcome potential functional redundancy among family members. We are examining the available mutants for altered photoresponses under various light conditions. Progress on functional analysis of this gene family in regulating Arabidopsis photomorphogenesis will be presented at the meeting.