The 2,441st Meeting of the Society

May 21, 2021 at 8:00 PM

Zoom Webinar

Bringing Back the American Chestnut Tree

How Biotechnology Can Be Applied to Conservation

William A. Powell

Director, American Chestnut Research & Restoration Project
Roosevelt Wild Life Station Scientist-in-Residence

Sponsored by PSW Science Member Tim Thomas

About the Lecture

The American chestnut (Castanea dentata) and chestnut blight is the classic example of what can happen when forests succumb to invasive pests and pathogens. Because of its environmental, economic, and cultural importance, many tools have been brought to bear on the chestnut blight problem over the past century.

Our team has focused on genetic engineering approaches to enhancing blight tolerance, involving the targeted addition of specific genes to confer tolerance to the chestnut genome.  All 38,000 naturally occurring genes remain the same, maintaining the full genetic complement required for growth and adaptation to the chestnut’s natural forest ecosystem.

The most promising gene tested to date encodes an oxalate detoxifying enzyme (oxalate oxidase, “OXO”), from the bread wheat, Triticum aestivum.  The OXO gene is found in many plants, where it plays a role in defense against parasites.  We found that this gene can confer enhanced blight tolerance in the American chestnut. The original blight tolerant trees grown with the OXO genes have not been outcrossed to susceptible American chestnut trees through three generations to date, increasing genetic diversity and local adaptation.  Environmental impact experiments have been completed and these trees are currently under federal review before being released to the public and to restoration programs.  This presentation will describe the program and its current progress toward restoring this keystone species and very beautiful tree to its native place in America’s forests.


Newhouse AE, Powell WA. Intentional introgression of a blight tolerance transgene to rescue the remnant population of American chestnut. Conservation Science and Practice. 2020;e348.

McGuigan, Linda, Patrícia Fernandes, Allison Oakes, Kristen Stewart, and William Powell. 2020. “Transformation of American Chestnut (Castanea Dentata (Marsh.) Borkh) Using RITA® Temporary Immersion Bioreactors and We Vitro Containers.” Forests 11: 1196.

Powell WA, Newhouse AE, Coffey V. 2019. Developing blight-tolerant American chestnut trees., In Perspectives on Engineering Plant for Agriculture, P. Arnold Editor, Cold Spring Harb Perspect Biol, doi:10.1101/cshperspect.a034587

Goldspiel, H. B., Newhouse, A. E., Powell, W. A., & Gibbs, J. P. (2019). Effects of transgenic American chestnut leaf litter on growth and survival of wood frog larvae. Restoration Ecology, 27:371-378

Chestnut project video:

About the Speaker

Bill Powell is Professor of Environmental Science and Forestry at the SUNY College of Environmental Sciences and Forestry, where he is Director of the American Chestnut Research & Restoration Project, and Scientist-in-Residence at the Roosevelt Wild Life Station.

Bill’s research focuses on the American Chestnut tree and the chestnut blight pathogen that has driven it almost to extinction.  He has studied the hypovirulence mechanisms of the fungus and has used classical and molecular genetic techniques to develop blight tolerant chestnut trees.

Bill has published widely on his work.

Among other honors and awards, Bill was named Forest Biotechnologist of the Year by the Institute of Forest Biotechnology.  He received the Exemplary Researcher Award bestowed by SUNY-ESF and the SUNY Chancellor’s Award for Research and Scholarship.

Bill earned a BS in Biology at Salisbury State University and a PhD in Biology at Utah State University.