Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

McCarthy, Elizabeth [1], Mohamed, Abeer [1], Litt, Amy [1].

The consequences of gene duplication: Functional divergence of APETALA1 and FRUITFULL in Arabidopsis thaliana.

Ancient gene duplications have shaped the evolution of floral development. One such duplication occurred at the base of the core eudicots in the APETALA1 lineage and resulted in euAP1 and euFUL gene clades. In Arabidopsis, both the APETALA1 (AP1) and FRUITFULL (FUL) genes promote floral meristem identity, whereas AP1 is involved in sepal and petal identity and FUL plays a role in fruit development. AP1 and FUL are expressed in mutually exclusive domains during floral development and also possess unique motifs within their proteins. Here, we examine the mechanism behind the functional divergence of AP1 and FUL in Arabidopsis thaliana, using promoter swap experiments to determine whether divergence in function between these two genes is due to differences in regulation or unique changes in coding sequence or both. Preliminary results suggest that FUL cannot substitute for AP1 function in petal identity, as petals are not formed in ap1 mutants transformed with a construct that contains the FUL coding sequence driven by the AP1 promoter. However, preliminary results suggest that these transformants have fewer flowers per pedicel compared to ap1 mutants, suggesting that the FUL protein can at least partially substitute for AP1 function in floral determinacy. We also investigate the role of a protein-modification motif in the AP1 protein, one of the motifs that differentiates AP1 and FUL proteins. Site-directed mutagenesis was performed to alter the motif to prevent modification of the AP1 protein, and ap1 mutants were transformed with a construct that contains the mutated AP1 coding sequence driven by the AP1 promoter. Transformants produce petals, so it appears that modification of the AP1 protein is not necessary for petal identity. Our results shed light on whether divergence in regulation or coding sequence drives divergence in function and elucidate the role that functional divergence of gene duplicates has on the evolution of flowering plants.

Broader Impacts:

1 - The New York Botanical Garden, Plant Genomics, 2900 Southern Blvd., Bronx, NY, 10458, USA

Keywords:
Floral development
functional divergence of gene duplicates
APETALA1
FRUITFULL
petal identity.

Presentation Type: Oral Paper:Papers for Topics
Session: 42
Location: Jasperwood/Riverside Hilton
Date: Wednesday, July 31st, 2013
Time: 11:00 AM
Number: 42004
Abstract ID:279
Candidate for Awards:None