Scientists tap tree genomes to discover adaptation strategies

After decades of extrapolating about gene function in trees based on gene function in a tiny, less complex plant, a team of scientists has sequenced whole genomes -- determined the DNA sequence of all the genes -- from 544 unrelated trees of the same species. 

The study identified gene sequences from Populus trichocarpa, to understand how trees adapt to different climates.

"Basically, most of our knowledge of what genes are important for environmental adaptation of trees has been educated guessing built on studies in the model plant, Arabidopsis, which is a member of the mustard family" said Amy Brunner, an associate professor of molecular genetics in Virginia Tech's College of Natural Resources and Environment.

To determine the impact of environment on growth, cuttings from trees in many wild populations were grown in research plots in four distinct environments from California to British Columbia.

Brunner is a co-author of an article in an August 2014 issue of Nature Geneticsabout the study, which identified gene sequences from Populus trichocarpa, commonly known as black cottonwood. One goal is to understand how trees adapt to different climates and to use that information to advance tree breeding for different environments.

"With this approach there is no need to have a preconceived notion of what genes are important," Brunner said. "Instead, existing natural variation in physical traits can be associated with genetic variation in all the genes in a tree. This work advances the first step -- the need to know which genetic variations are important to adaptation. Then you have to know why that variation is important."