| Abstract Detail
Thursday Morning Contributed Talks Irish, Vivian [1]. Diversification of tomato APETALA3 genes. IN Arabidopsis thaliana, the floral homeotic APETALA3 (AP3) gene encodes a MADS-box transcription factor that is required for specifying petal and stamen identities. Here we show that tomato possesses two AP3 lineage genes, LeAP3 and LeTM6, that have diversified in their functional roles. We have identified a loss of function insertional mutation in LeAP3 which affects both petal and stamen organ identity specification, resulting in homeotic transformations of these organs. In contrast, an RNAi-induced reduction in LeTM6 function results in flowers with homeotic defects primarily in stamen development. Our data suggests that the differences in function between these gene duplicates can be ascribed partly to different domains of expression, as well as differences in the biochemical capabilities of the encoded gene products. Rescue experiments show that when these genes are overexpressed in an equivalent domain, they both can partially rescue the leap3 mutant, indicating that relative levels as well as spatial patterns of expression contribute to differences in function. These results suggest that LeTM6 has a qualitatively different role in floral development, as compared to LeAP3. Furthermore, these results support the idea that the ancestral role of the AP3 lineage genes was in specifying stamen development, and that duplication and divergence in the AP3 lineage allowed for the acquisition of a role in petal specification in the core eudicots.
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1 - Yale University, Molecular, Cellular and Developmental Biology, 266 Whitney Ave, PO Box 208104, New Haven, CT, 06520, USA
Keywords:
flower development
MADS box genes
tomato.
Session: SOL06-7
Location: Ballroom AB/Monona Terrace
Date: Thursday, July 27th, 2006
Time: 10:30 AM
Abstract ID:57 |
