• use the poplar genome to isolate poplar versions of all genes known to regulate root development in other model species;
• identify additional novel candidate genes by screening existing populations of Populus, which have had their gene expression altered in various ways, to identify patterns of lateral root formation;
• test the effects of over-expressing and silencing all candidate genes in two genotypes of poplar that exhibit contrasting rooting responses;
• evaluate the effects of these genetic manipulations on root formation and architecture; and
• conduct analyses to identify metabolic alterations that may be associated with the above genetic manipulations.

The project will benefit carbon sequestration in three ways. (1) Because lateral roots account for the bulk of the treeís below-ground biomass, stimulating their proliferation will promote carbon sequestration in the soil. (2) Increased lateral root production will likely enhance overall plant growth via more efficient resource acquisition. (3) Given that lateral root production is very similar to adventitious rooting, the many genes involved in regulating lateral root formation will also likely control adventitious root initiation. The ability to vegetatively propagate forest trees, through adventitious rooting, will allow growers to fully capture genetic gains that have already been achieved through conventional breeding. Growing elite germplasm may, in turn, lead to more efficient carbon sequestration.