Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Boyden, Geraldine [1], Hardej, Diane [2], Litt, Amy [3], Howarth, Dianella [1].

CYCLOIDEA-like genes are implicated in development and floral patterning in Fedia cornucopiae (Valerianaceae).

Angiosperm diversification has been facilitated in part by the independent evolution of bilateral symmetry (zygomorphy, monosymmetry) from actinomorphic ancestors in many groups of flowering plants. Recent breakthroughs point to the role of CYCLOIDEA-like (CYC-like) genes in floral symmetry and their repeated co-option in developmental patterning in independent lineages. The CYC-like genes belong to the ECE clade of class II TCP family of transcription factors and have been shown to function similarly in Antirrhinum,Gerbera, Lotus, and Pisum. Recently, studies in Opithandra (Gesneriaceae) address the role of CYC in establishing stamen number. In this study, the virus-induced gene silencing (VIGS) strategy is used to investigate the role of CYC-like genes in Fedia cornucopiae (Valerianaceae). Various copies of CYC-like genes (CYC1, CYC2A, CYC2B, CYC3A, CYC3B) and their combinations will be analyzed to provide clues for their role in development, establishing floral patterns in petals and their possible interactions among the other gene copies (paralogs) within the lineage. The relative levels of gene expression will be analyzed by quantitative real-time (RT)-PCR and phenotypic analyses by light and electron microscopy. Preliminary data have shown marked variations in development of CYC2A and CYC2B mutants compared to wildtype. Flower buds of these mutants were opened prematurely (while green) displaying prominent underdeveloped stamen and the petals acquired the customary pink coloration during the later stages of development. Flowers of the mutants were predominantly actinomorphic with more petals compared to the normal pentapetalae form. In addition, at least one or two commonly aborted stamens were restored. Data from these analyses will allow us to explore how duplications of CYC-like genes correlate to evolutionary changes within Dipsacales and on a broader scale, how this phenomenon leads to novel phenotypic traits in core eudicots.

Broader Impacts:

1 - St. John's University, Biological Sciences, 8000 Utopia Parkway, Jamaica, Queens, NY, 11439, USA
2 - St. John's University, Pharmaceutical Sciences, 8000 Utopia Parkway, Jamaica, Queens, NY, 11439, USA
3 - The New York Botanical Garden, 200th St and Southern Blvd, Bronx, New York, 10458, USA

Keywords:
CYCLOIDEA
VIGS
Dipsacales
floral development
flower bilateral symmetry
Phenotypic traits.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM
Number: PEV004
Abstract ID:496