Plants like petunia and arabidopsis are suitable models for these studies presenting large differences and being easy to isolate mutants and to produce transgenics. We analyse sets of genes involved in both pigmentation pattern and inflorescence architecture to unravel whether different expression is the consequence of different in their promoters or in the protein regulating their transcription. This gives insights in how genes determine the body plan of an organism and which changes in the same genes led to the different patterning during evolution. Petunia offers the possibility to easily isolate mutants for any gene thanks to a very active set of transposons which, by jumping around and landing in new places in the genome, continuously generate new mutants.
Flower pigmentation and inflorescence architecture have been for many years the category for which we have isolated the most mutants, as these are the two main subject of studies for us, however, also other type of mutants are present in the collection.
The colour displayed by flowers gives a great opportunity to approach all kinds of phenomena related to gene expression regulation, as any change result in an easy to score change in flower colour. Using these tools, our group has cloned and characterised several genes of the pathway for the production and accumulation of anthocyanins (the main plant pigments), transcription factors regulating expression of such a pathway, genes involved in the regulation of environment in cellular compartments and discovered gene silencing (van der Krol, A.R., et al. (1988). Nature 333, 866-869).