The fully linked HTML version of this article has now been published.
Development ePress online publication date 19 Oct 2005
doi: 10.1242/dev.02085
Research article
Evolution of regulatory interactions controlling floral asymmetry
Maria Manuela R. Costa,
Samantha Fox,
Andy I. Hanna,
Catherine Baxter,
and
Enrico Coen*
* Author for correspondence (e-mail: enrico.coen{at}bbsrc.ac.uk)
A key challenge in evolutionary biology is to understand how new morphologies can arise through changes in gene regulatory networks. For example, floral asymmetry is thought to have evolved many times independently from a radially symmetrical ancestral condition, yet the molecular changes underlying this innovation are unknown. Here, we address this problem by investigating the action of a key regulator of floral asymmetry, CYCLOIDEA (CYC), in species with asymmetric and symmetric flowers. We show that CYC encodes a DNA-binding protein that recognises sites in a downstream target gene RADIALIS (RAD) in Antirrhinum. The interaction between CYC and RAD can be reconstituted in Arabidopsis, which has radially symmetrical flowers. Overexpression of CYC in Arabidopsis modifies petal and leaf development, through changes in cell proliferation and expansion at various stages of development. This indicates that developmental target processes are influenced by CYC in Arabidopsis, similar to the situation in Antirrhinum. However, endogenous RAD-like genes are not activated by CYC in Arabidopsis, suggesting that co-option of RAD may have occurred specifically in the Antirrhinum lineage. Taken together, our results indicate that floral asymmetry may have arisen through evolutionary tinkering with the strengths and pattern of connections at several points in a gene regulatory network.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:

|
 |

|
 |
 
W. S. Armbruster, J. Lee, and B. G. Baldwin
Plant and Insect Biodiversity Special Feature: Macroevolutionary patterns of defense and pollination in Dalechampia vines: Adaptation, exaptation, and evolutionary novelty
PNAS,
October 27, 2009;
106(43):
18085 - 18090.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. G. Howarth and M. J. Donoghue
Duplications and Expression of DIVARICATA-Like Genes in Dipsacales
Mol. Biol. Evol.,
June 1, 2009;
26(6):
1245 - 1258.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. S. Soltis, S. F. Brockington, M.-J. Yoo, A. Piedrahita, M. Latvis, M. J. Moore, A. S. Chanderbali, and D. E. Soltis
Floral variation and floral genetics in basal angiosperms
Am. J. Botany,
January 1, 2009;
96(1):
110 - 128.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
I. Efroni, E. Blum, A. Goldshmidt, and Y. Eshed
A Protracted and Dynamic Maturation Schedule Underlies Arabidopsis Leaf Development
PLANT CELL,
September 1, 2008;
20(9):
2293 - 2306.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. Jabbour, C. Damerval, and S. Nadot
Evolutionary Trends in the Flowers of Asteridae: Is Polyandry an Alternative to Zygomorphy?
Ann. Bot.,
August 1, 2008;
102(2):
153 - 165.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. K. Broholm, S. Tahtiharju, R. A. E. Laitinen, V. A. Albert, T. H. Teeri, and P. Elomaa
A TCP domain transcription factor controls flower type specification along the radial axis of the Gerbera (Asteraceae) inflorescence
PNAS,
July 1, 2008;
105(26):
9117 - 9122.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Busch and S. Zachgo
Control of corolla monosymmetry in the Brassicaceae Iberis amara
PNAS,
October 16, 2007;
104(42):
16714 - 16719.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C.-H. Tsou and S. A. Mori
Floral organogenesis and floral evolution of the Lecythidoideae (Lecythidaceae)
Am. J. Botany,
May 1, 2007;
94(5):
716 - 736.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. R. Yadav, K. Prasad, and U. Vijayraghavan
Divergent Regulatory OsMADS2 Functions Control Size, Shape and Differentiation of the Highly Derived Rice Floret Second-Whorl Organ
Genetics,
May 1, 2007;
176(1):
283 - 294.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Damerval, M. L. Guilloux, M. Jager, and C. Charon
Diversity and Evolution of CYCLOIDEA-Like TCP Genes in Relation to Flower Development in Papaveraceae
Plant Physiology,
February 1, 2007;
143(2):
759 - 772.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H.-C. Lu, H.-H. Chen, W.-C. Tsai, W.-H. Chen, H.-J. Su, D. C.-N. Chang, and H.-H. Yeh
Strategies for Functional Validation of Genes Involved in Reproductive Stages of Orchids
Plant Physiology,
February 1, 2007;
143(2):
558 - 569.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. G. Howarth and M. J. Donoghue
Phylogenetic analysis of the "ECE" (CYC/TB1) clade reveals duplications predating the core eudicots
PNAS,
June 13, 2006;
103(24):
9101 - 9106.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
X. Feng, Z. Zhao, Z. Tian, S. Xu, Y. Luo, Z. Cai, Y. Wang, J. Yang, Z. Wang, L. Weng, et al.
From the Cover: Control of petal shape and floral zygomorphy in Lotus japonicus
PNAS,
March 28, 2006;
103(13):
4970 - 4975.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Q. C. B. Cronk
Legume flowers bear fruit.
PNAS,
March 28, 2006;
103(13):
4801 - 4802.
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. McSteen
Branching Out: The ramosa Pathway and the Evolution of Grass Inflorescence Morphology.
PLANT CELL,
March 1, 2006;
18(3):
518 - 522.
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2005