Aimée Classen & Nathan Sanders

UTK ecology and evolutionary biology

Do genes respond to climate change?

We can see that plant species respond differently to varied environments. Cacti do better in deserts than they do in tundra, and spruce trees do better at the tops of mountains than in tropical forests, says JDRD team leader Aimée Classen.

On a global scale, altered precipitation patterns and warming trends bring large shifts in species distribution, say Classen and co-team leader Nathan Sanders. But is there any evidence that individuals of the same species respond differently to different environments?

"Individuals in the same species can be very different—just look around at a room of people—and have very different traits, such as leaf size and leaf color. We are interested in knowing if these trait variations alter the way an individual responds to environmental change," Classen says.

Classen, Sanders, and their LDRD counterpart David Weston speculate that one way to get at that information would be to link genes to ecosystem functions, such as the quantity of carbon absorbed by a plant or the amount of energy produced by photosynthesis.

Global warming aside, the Earth's geological processes responsible for fluctuating ecosystems have caused glaciers to advance and retreat and turned great inland seas to grassy plains. In their wake, as plants and animals evolved they developed and retained a core of physiological mechanisms to protect themselves from stressful changes in the environment. These two projects help identify the genetic controls underlying those adaptive traits.

"If we can associate gene modules with environmental stress, such as warming, and correlate these modules to plant traits, we might be able to use that information to identify and relate same-species responses to the environment," Classen says.

During year one, Weston's group began to identify evolutionarily conserved groups of heat-stress-and-recovery genes that are associated with assimilating CO2 and absorbing energy in three well-know (model) plant species. Classen and Sanders extended the approach to a non-model species, Solidago altissima (goldenrod).

"If we can specify the genetic controls underlying adaptive traits, then we might be able to use genetic indicators as an analogue to predict whether, and how, particular species can adapt to changing climates," Classen says.

Additional informatrion on Classen and Sander's research can be found on their individual and departmental web pages: http://eeb.bio.utk.edu/classen.asp; http://eeb.bio.utk.edu/sanders.asp.