July 9, 2009

Genes that change flowers’ color are ID’d

University of California-Santa Barbara scientists say they have identified the genes that are responsible for changing a flower's colors.

Professor Scott Hodges and graduate student Nathan Derieg said they studied red columbines pollinated by hummingbirds and white or yellow columbines pollinated by hawkmoths to document the evolution of such flowers in North America.

They said their research indicates a color shift from red to white or yellow has occurred five times in that region.

What is important in this research is that hawkmoths mostly visit and pollinate white or pale flowers, Hodges said. We have shown experimentally that hawkmoths prefer these paler colors.

When a plant population shifts from being predominantly hummingbird-pollinated where flowers are red, to hawkmoth-pollinated, natural selection works to change the flower color to white or yellow, he explained.

Ultimately we want to know if evolution can be predictable, added Hodges. In other words, we want to know if each time there is an evolutionary change in flower color, does it happen in the same way? Having identified all the genes that are intimately involved with making red and blue columbines now allows us to determine how these evolutionary transitions have occurred.

The study was published recently in the Proceedings of the National Academy of Sciences.