Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 109, Issue 34, Pages E2267-E2275Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1203686109
Keywords
floral organ identity genes; MADS-box genes; solo long terminal repeats; RNA silencing
Categories
Funding
- National Science Foundation Grant [IOS-1121669]
- Research Experience for Undergraduates-linked-to-National Science Foundation Grant [IOS-RIG 0818836]
- Carl Zeiss Stiftung
- Division Of Integrative Organismal Systems
- Direct For Biological Sciences [1121669] Funding Source: National Science Foundation
Ask authors/readers for more resources
In the model plant Arabidopsis thaliana, a core eudicot, the floral homeotic C-class gene AGAMOUS (AG) has a dual role specifying reproductive organ identity and floral meristem determinacy. We conduct a functional analysis of the putative AG ortholog ThtAG1 from the ranunculid Thalictrum thalictroides, a representative of the sister lineage to all other eudicots. Down-regulation of ThtAG1 by virus-induced gene silencing resulted in homeotic conversion of stamens and carpels into sepaloid organs and loss of flower determinacy. Moreover, flowers exhibiting strong silencing of ThtAG1 phenocopied the double-flower ornamental cultivar T. thalictroides 'Double White.' Molecular analysis of 'Double White' ThtAG1 alleles revealed the insertion of a retrotransposon causing either nonsense-mediated decay of transcripts or alternative splicing that results in mutant proteins with K-domain deletions. Biochemical analysis demonstrated that the mutation abolishes protein-protein interactions with the putative E-class protein ThtSEP3. C- and E-class protein heterodimerization is predicted by the floral quartet model, but evidence for the functional importance of this interaction is scarce outside the core eudicots. Our findings therefore corroborate the importance and conservation of the interactions between C- and E-class proteins. This study provides a functional description of a full C- class mutant in a non-core (basal) eudicot, an ornamental double flower, affecting both organ identity and meristem determinacy. Using complementary forward and reverse genetic approaches, this study demonstrates deep conservation of the dual C- class gene function and of the interactions between C- and E-class proteins predicted by the floral quartet model.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available