Abstract Detail

Development and Structure

Mustacchio, Theresa A. [1], Tong, Jingjing [2], Savriama, Yoland [3], Berger, Brent Alexander [4], Howarth, Dianella G. [5].

Knockdown of floral symmetry in Fedia graciliflora.

Shifts between radial symmetry (actinomorphy) and bilateral symmetry (zygomorphy) in flowers have occurred multiple times independently within angiosperms. These morphological shifts are commonly associated with increased pollinator specialization and speciation rates. Evidence from studies across angiosperms indicate that the CYCLOIDEA (CYC)-like genes play a role in patterning bilaterally symmetrical flowers. Three core eudicot clades of CYC-like genes have been identified: CYC1, CYC2 and CYC3, with CYC2-like genes being the most involved in dorsal specialization. To further investigate the CYC-like genes and the regulation of bilateral symmetry we used the non-model plant, Fedia graciliflora (Caprifoliaceae). Fedia species have strongly bilaterally symmetrical flowers with morphologically distinct dorsal (upper), lateral, and ventral (lower) petals and only two functional stamens. Fedia has evolved within the Valerianella, a group with pseudo-radially symmetric flowers with three functional stamen, providing a model for studying the evolution of strong bilateral symmetry. In this study, VIGS was used to study morphological differences in floral symmetry by knocking down each of these separately: FgCYC2A, FgCYC2B, FgCYC3A, and FgCYC3B. The down-regulated plants were assayed using geometric morphometrics combined with tools of multivariate statistical shape analysis to quantify shape changes.

1 - St. John's University, 8000 Utopia Pkwy, Jamaica, NY, 11439, USA
2 - St. John's University, Biological Sciences, 8000 Utopia Pkwy, Jamaica, NY, 11439, United States
3 - Max Planck Institute, Evolutionary Biology, August-Thienemann-Straße 2, 24306 Plön, Germany
4 - St. John's University, 8000 Utopia Parkway, Queens, NY, 11439, United States
5 - St. John's University, Department Of Biological Sciences, St. Albert Hall Rm 257, 8000 Utopia Pkwy, Jamiaca, NY, 11439, United States

Keywords:
Floral development
Morphometrics
CYCLOIDEA
floral morphology.

Presentation Type: Oral Paper
Session: DS2, Development and Structure II
Location: /
Date: Wednesday, July 21st, 2021
Time: 10:45 AM(EDT)
Number: DS2004
Abstract ID:966
Candidate for Awards:Katherine Esau Award