At the turn of the 20th century, the American chestnut tree (Castanea dentata) was perhaps the single most economically and ecologically valuable tree species in North America. Wholesale devastation and near extinction of the tree has since been caused by an invasive species of fungus that was inadvertently introduced by human activity. The team's goal is to restore the American chestnut tree to the North American forest, and to regain the tremendous economic and ecological impacts the species provides for the benefit of mankind. Utilizing advanced genetic engineering (GE) techniques, ESF researchers have developed a blight-resistant American chestnut tree. The science is truly innovative, providing an approach that produces a blight-resistant tree while not harming the fungus. The tree can survive in the presence of the fungus because it expresses an enzyme that neutralizes the oxalic acid released by the fungus that otherwise would damage the tree and eventually kill it. The enzyme has no direct effect on the fungus itself, which continues to live and reproduce normally. This is important because it bypasses any strong selective pressure for the fungus to overcome this type of resistance and therefore is sustainable. ESF’s research orchards are currently growing blight-resistant trees under strict regulatory control, focusing on preserving genetic diversity of existing trees and incorporating regional acclimation to variations in climate. The critical next step in advancing restoration efforts is to complete the regulatory review process with government agencies. The funds from this grant will be used to support key personnel and activities to acquire regulatory agency approvals to enable future distribution.