Plant evolution expert Peter Tiffin has studied how plants hold their own against herbivores and other enemies.
Evolving with the climate
Understanding how plants evolve could suggest ways to help them adapt to global climate change.
Mary K. Hoff
Feb. 2, 2007
At first glance it may seem like a charmed life. But in reality it's not all that easy being a plant.
Anchored firmly by your roots, you can't outrun, dodge or hide from organisms that aim to eat you. So instead you develop defenses: tough tissue, toxins, thorns, spines. And what do your nemeses do in turn?
Develop ways to outsmart them. This evolutionary pas de deux holds plenty of intrigue for Peter Tiffin, assistant professor in the Department of Plant Biology. Tiffin started his scientific career studying plants from the perspective of crop production.
But he soon found himself captivated not so much by the organisms themselves, but by the molecular changes in their genes that allow them to endure in and adapt to a changing world. Among the most fascinating genetic characteristics Tiffin has studied so far are those that help plants hold their own against herbivores and other enemies.
"I want to understand how biotic interactions shape the evolution of organisms," Tiffin says. "As far as a strong evolutionary force, being eaten is pretty strong."
Tiffin has been looking at molecular genetic differences in two species of teosinte, a Central American grass that is the ancestor of modern corn. By comparing the DNA that codes for defenses such as digestion-inhibiting and antifungal proteins in different populations, he's been able to gain insights into a variety of evolutionary strategies for staying alive in a world replete with plant-eaters.
"We consider Peter Tiffin one of the top young stars in the plant molecular evolution field," says Peter Snustad, acting head of the Department of Plant Biology. "His work on the evolution of plant defense genes and host-parasite interactions is cutting edge."
Tiffin is also investigating the genetic implications for genetic variation and selection of increasing atmospheric carbon dioxide. To study that, he planted 6,000 Arabidopsis thaliana plants (the botanical equivalent of white mice) in research plots exposed to higher-than-normal carbon dioxide at the College of Biological Sciences' Cedar Creek Natural History Area research facility.
"There are suggestions that carbon dioxide changes the evolutionary trajectory," he says. "We hope to test this idea as well as identify chromosomal regions contributing to differences among genotypes' response to carbon dioxide."
In another study, Tiffin is looking at the relationship between molecular genetic variation and growth range in Clarkia xantiana, a purple-petaled flower found in the Sierra Nevada of California.
"With global climate change, there's a lot of evidence that species ranges will shift," he says. Improved understanding of the link between genetics and range, he says, may prove valuable to predicting-and potentially boosting-plants' ability to adapt to such change.