Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Martinez-Gomez, Jesus [1], Galimba, Kelsey [2], Sullivan, Alessandra [3], Coté, Erin [4], Di Stilio, Veronica [5].

Natural homeotic mutants and genetic control of floral organ identity in a ranunculid.

Long prized for their beauty, double flower varieties comprise the familiar forms of popular plants such as roses and peonies. Homeotic mutants are especially useful in emerging model plants, where they have been used instead of less-feasible gene perturbation or mapping experiments, to study gene function. Here we compare six naturally occurring homeotic floral mutants of Thalictrum (Ranunculaceae), five newly characterized, to investigate the cause of the altered phenotypes and to enquire about the genetic regulation of floral organ identity in this non-core eudicot. This forward genetic approach included comparative flower developmental morphology, floral organ identity gene expression and sequence analysis, and identification of MADS box transcription factor (TF) binding motifs and protein-protein interaction (PPI) motifs. Mutants exhibited altered expression of floral MADS box genes following gene duplication, revealing instances of neo- functionalization (e.g., B-class genes expressed ectopically in sepals), partial redundancy (in E-class genes) or sub-functionalization (in C-class genes). Differential expression of C class genes in three double flower mutants was associated with signs of transposon activity within the regulatory intron of AGAMOUS (AG), leading to varying degrees of indeterminancy in flowers. Single amino acid substitutions were mapped to MIKC domains, but appeared unlikely to affect DNA binding or protein-protein interactions. Moreover, a lack of deleterious mutations in the coding region of candidate floral MADS box genes suggests that upstream cis-regulatory or trans-acting mutations are at play. Finally, we inferred modified “BCE” models for the mutants and contextualized our results within the growing literature on Ranunculales flower development.

1 - Cornell University, Plant Biology, Ithaca, NY, 14853, USA
2 - 15 Gray Fox Rd, Harpers Ferry, WV, 25425, United States
3 - NanoString Technologies, Inc.
4 - University of Washington
5 - University Of Washington, Biology, 549 Life Sciences Building, PO BOX 351800, Seattle, WA, 98195, United States

Keywords:
Evolution of development
Ranunculaceae
Mutants
Transposable Element.

Presentation Type: Oral Paper
Session: EVDV1, Evolutionary Developmental Biology (Evo-Devo)
Location: Tucson E/Starr Pass
Date: Monday, July 29th, 2019
Time: 3:00 PM
Number: EVDV1007
Abstract ID:635
Candidate for Awards:Katherine Esau Award