Laboratory of Plant Systematics
Dries Vekemans
Evolution of nectaries: expression and function of CRABS CLAW
Introduction
After finishing my Master thesis at the Laboratory of Plant Systematics (Heterotopic petaloidy and floral ontogeny in Davidia involucrata) the Fund for Scientific Research Flanders (FWO-Vlaanderen) gave me the opportunity to continue doing scientific research as a PhD-Student. In this PhD-thesis I will study the role of the gene CRABS CLAW (CRC) as a key regulator in the development of nectaries.
Nectaries are secretory organs that are widely present in flowering plants and function to attract pollinators. In the model plant Arabidopsis, CRABS CLAW is required for the specification of nectaries. Additional studies in several core eudicot species have shown that CRC expression is conserved in morphologically different nectaries and is required for nectary development in both rosids and asterids, two major lineages of eudicots. However, in Aquilegia, a basal eudicot species, no evidence of CRC expression was found. As the ancestral function of CRC possibly lies in the regulation of carpel development, it may have been co-opted as a regulator of nectary development within the eudicots, concomitant with the association of nectaries with reproductive organs in derived lineages (Lee et al., 2005).
Goals
In order to gain further insight into this proposed scenario, we study the role of CRC in a broad phylogenetic context through comparative expression and functional studies.
We focus on basal asterids (Ericales and Cornales) to study the relationship between the evolution of CRC and nectaries. Different techniques like qPCR, in situ hybridization and Virus Induced Gene Silencing (VIGS) will be used. Because VIGS is a useful tool to study the function of genes, it is our aim to test the potential of this technique in several representatives of basal asterids (e.g. Impatiens, Cyclamen, Primula). In a broader phylogenetic context, the search for the origin of CRC as a regulator of nectaries during angiosperm evolution will be addressed by using the same techniques.
