Evolution experiments with flowers

Evolution uses every chance it gets to try something new. Dutch researcher Anneke Rijpkema investigated how petunia flowers are formed and discovered that nature is even more varied than the naked eye can spot. The genes involved in flower formation can function differently in different species. Evolution has discovered a system that works, but within that system it continues to innovate.

Up until now, research into the regulation of flower formation focused mostly on two model species: Arabidopsis and Anthirrhinum. Yet according to Rijpkema that is not enough to gain a complete picture. She investigated Petunia hybrida, related to plants such as the tomato and potato. Although the petunia flower structure is similar to that of Arabidopsis thaliana, there are considerable differences in how the flowers of these plants are formed. The result is more or less the same, yet in the process preceding this there are considerable differences. So there is even more variation in the natural world than the naked eye can spot.

Rijpkema analysed which genes are responsible for the flower formation in petunia. She did this, for example, by examining mutants: flowers in which a gene no longer functions, as a result of which they acquire a different appearance. This enabled her to determine the exact function of each gene. The developmental biologist discovered, for example, that gene duplication - the process in which two or more copies of a gene are made - plays a major role in the development of variation in flower development.

Besides unveiling how evolution works in plants, Rijpkema's research also reveals how plants function now. This is particularly interesting for breeders. Knowledge of flower formation can enable them to change a plant. Furthermore, knowledge about the petunia can also provide insights about related plant species such as the potato and tomato.

Rijpkema carried out her research at Radboud University Nijmegen with a grant from NWO. In 2008, she received a Rubicon grant from NWO to carry out research at the University of Helsinki. This time she is working on gerberas.