Abstract Detail

A Broader view for Plant EvoDevo: novel approaches for diverse model systems

Melzer, Rainer [1], Ruempler, Florian [2], Haerter, Andrea [2], Theissen, Guenter [2].

Turning a loss into a gain: Reduction of protein interactions among MADS-domain transcription factors may have facilitated diversification of flowering plants.

Homeotic MADS-domain transcription factors are key determinants of floral organ identity. These proteins exert their function by forming dimeric and tetrameric complexes that bind to DNA and regulate target gene activity. Protein complex formation is highly specific in core eudicots: certain proteins form heterodimers or heterotetramers with a few selective partners only. One well-studied example are DEF- and GLO-like proteins. These determine petal and stamen identity and form heterodimers exclusively with each other in core eudicots.
To investigate the evolutionary origin of the interaction specificity among MADS-domain proteins we analysed interaction patterns of orthologues of floral homeotic proteins from early diverging angiosperms and gymnosperms. Intriguingly, protein interactions are considerably less specific in these species. For example, not only heterodimerization but also homodimerization of DEF- and GLO-like proteins as well as interactions with other MADS-domain transcription factors are observed. Ancestral character-state reconstruction indicates that the network of MADS-domain protein interactions was in general more promiscuous early during angiosperm evolution and that a number of interactions were lost in the lineages leading to core eudicots and monocots. The loss of interactions correlates with an increased canalization of the floral bauplan. We propose that this canalization was a prerequisite for the diversification of floral form. Eventually, therefore, a reduction in the number of protein interactions among MADS-domain proteins may have facilitated the origin of species diversity in core eudicots and monocots.

Related Links:
web page Rainer Melzer

1 - University College Dublin, School of Biology and Environmental Science, Science Centre West, Belfield, Dublin 4, Ireland
2 - Friedrich Schiller University Jena, Department of Genetics, Philosophenweg 12, Jena, 07743, Germany

Keywords:
flower evolution
MADS-domain protein
protein protein interactions
ancestral state reconstruction.

Presentation Type: Symposium Presentation
Session: SY02
Location: Salon 11/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 10:45 AM
Number: SY02007
Abstract ID:1077
Candidate for Awards:None