Di Stilio's group studied Thalictrum thalictroides. Known in the nursery trade as Anemonella thalictroides and rue anemone, the spring-flowering plant is native to the woods of Northeastern U.S. It belongs to the family Ranunculaceae, a sister lineage of the Eudicots. Eudicots today include 70 percent of all flowering species.
"The plants we've chosen to study possess ancestral floral traits and are sister to the core Eudicots that have model plants used by biologists such as Arabidopsis thaliana and Antirrhinum majus, or snapdragon," Di Stilio said. "But the plants in our study belong to a more ancient lineage. We're interested in evolution of flowers so we want to look at something that is a little bit different, that might inform us about how development has been tweaked over time to produce change."
The scientists compared the class of genes that direct the development of certain sexual reproduction organs in wild-type Thalictrum with that of the cultivated double-flower version known as Double White. In the mutant, Galimba spotted part of a transposon, jumping genes that can move about the organism's genome, sitting in the gene that affects development of reproductive organs. The protein produced by the mutant gene lacks some of the amino acids found in wild-type plants and the scientists hypothesize that it's not the right length to interact with other proteins normally, Galimba said.
The researchers then did a second check on the findings by using a technique called viral induced gene silencing to knock down the properly functioning gene in a wild-type plant. The resulting blossom looked very similar to the Double White mutant.
"The flower is one of the key innovations of flowering plants. It allowed flowering plants to coevolve with pollinators mainly insects, but other animals as well and use those pollinators for re
|Contact: Sandra Hines|
University of Washington