Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Almeida, Ana Maria [1], Yockteng, Roxana [1], Otoni, Wagner [2], Specht, Chelsea [3].

Evolution of the AGAMOUS gene family in the Zingiberales: Insights into androecial petaloidy.

The Zingiberales is an order of tropical monocots that comprises approximately 2,500 species. The evolution of floral morphology in this group is marked by a striking reduction in the number of fertile stamens, which is, in turn, associated with increased petaloidy of the infertile androecial members. The molecular basis of floral organ identity, as defined by the ABC model, has been largely determined for model species such as Arabidopsis thaliana and Antirrhinum majus. In this model, combinatorial expression of A, B, and C class genes specify the identity of different floral organs. C-class genes are represented by the AGAMOUS gene family, and have been implicated in the specification of stamen (together with B class genes) and gynoecium identity. In Arabidopsis thaliana, ag-11 mutants show petaloid stamens, suggesting that AGAMOUS might be an important agent in androecial petaloidy. Here, we test the hypothesis that duplication followed by divergent copy-specific expression is correlated with the evolution of androecial petaloidy in the Zingiberales. Our results point to at least one event of gene duplication after the divergence of the Zingiberales from its sister group, leading to distinct ZinAG-1 and ZinAG-2 copies. Sequence divergence within ZinAG-1 is striking and might play a role in androecial petaloidy in the order. AGAMOUS gene expression in the Zingiberales differs from previously described patterns in Arabidopsis, and are difficult to correlate to petaloidy in the gingers. Finally, we suggest that changes in the regulatory regions of the AGAMOUS genes may be a driving force underlying the evolution of androecial petaloidy in the Zingiberales.

Broader Impacts:

1 - University California, Berkeley, PMB, Specht Lab, 431 Koshland Hall, Berkeley, CA, 94720, USA
2 - Universidade Federal de Viçosa, Departamento de Botanica, Viçosa, MG, Brazil
3 - University of California Berkeley, 111 Koshland Hall, MC 3102, Berkeley, CA, 94720, USA

Keywords:
AGAMOUS
Petaloidy
Zingiberales
Floral development
Morphological evolution.

Presentation Type: Oral Paper:Papers for Topics
Session: 47
Location: Jasperwood/Riverside Hilton
Date: Wednesday, July 31st, 2013
Time: 4:30 PM
Number: 47012
Abstract ID:86
Candidate for Awards:Katherine Esau Award