Into the Wild: GMOs head for the forest

If approved, the genetically engineered "Darling 58" American chestnut will be the first GE forest tree planted in the wilds of North America.

by Lucy Sharratt

American chestnut, Halifax Public Gardens, Nova Scotia | Photo ©CBAN 2020

Genetic engineering is set to leave the farm for the forest. After over twenty years of growing genetically engineered (GE or genetically modified) crop plants in North America, researchers are now proposing to plant GE trees in the forests of eastern US and Canada. This is a precedent-setting request that asks us to accept, even embrace, genetically modified organisms (GMOs) in the wild.

The first genetically engineered forest tree is now being considered for release into the wild. The US Department of Agriculture is now assessing a proposal from university researchers to plant a GE American chestnut tree in forests. The researchers have genetically engineered the tree to tolerate the blight Cryphonectria parasitica that decimated American chestnut populations in Canada and the US in the 1900’s.

This GE tree is engineered with a gene from wheat, key to creating the blight-tolerant trait, as well as genetic material from four other species: a plant related to mustard, two different bacteria, and a plant virus. Together, the use of this new genetic material has resulted in the “Darling 58” GE American chestnut tree.

Releasing this genetically engineered tree into forest ecosystems would be a large-scale, open-air experiment.

The researchers propose to widely plant Darling 58 to “restore” the American chestnut. The plan is to release the GE trees so that they spread freely in the wild and cross with any remaining wild American chestnuts, passing blight-tolerance to future generations.

Canada’s American chestnut

Now endangered in Canada and almost extinct in the US, American chestnuts were once a quarter of all the trees in the mixed deciduous forests of eastern North America. Their natural range extends from Florida all the way into southern Ontario, and is projected to move further north in Ontario and through Quebec and the Maritimes before the end of the century, due to climate change.

The tree can also grow outside its range. For example, trees have already been identified or initiated by conservationists in eastern Ontario, Quebec, Nova Scotia, Prince Edward Island, and British Columbia. Surveys have found more large American chestnut trees in Canada than reported in the US.1

Restoration underway in Canada

In fact, there is promising restoration work in Canada led by conservation groups and teams of volunteers. This work has been underway for decades, focussed on conventional breeding with other chestnut species and identifying remaining wild individuals.2

However, the developers of Darling 58 say, “In the future, we also anticipate regulatory submissions to the Canadian Food Inspection Agency (CFIA) and Health Canada.”3 The Canadian Biotechnology Action Network asked if regulators are already conducting such a risk assessment but was told by the Minister of Agriculture and Agri-Food that, “due to privacy considerations, the Canadian Food Inspection Agency (CFIA) does not disclose the status of applications that have been submitted or are currently under review.”4 Meanwhile, a US evaluation process is underway, with the release of a 290-page document from the developers and an associated public comment period.5

A large-scale open-air experiment

If approved, this GMO will be the first GE forest tree planted in the wilds of North America. However, science does not allow us to comprehensively assess the risks of releasing this or any other GE tree. We simply cannot know what will happen in highly complex forest ecosystems, subject to climate change and other pressures, over the long life-span and multiple generations of these organisms. American chestnut trees can live for over 200 years.

Furthermore, there is no assurance that the GE trait for blight-tolerance will actually work. The trait may not be stable over the long life of the trees, especially when faced with variable conditions in the wild. Additionally, the survival of American chestnuts is challenged by at least one other lethal pathogen as well as other stresses. The technological fix of a GE blight-tolerant trait, even if it succeeds, may not be sufficient to save the American chestnut.

All of these unknowns mean that releasing this genetically engineered tree into forest ecosystems would be a large-scale, open-air experiment.

Uncontrolled experiment, no recall

There would also be little chance to stop this experiment once started. There would be little or no potential to track this GE tree in the wild or reverse its spread, especially because the developers say they will give the GE tree to the public and non-profit groups to plant freely. Monitoring all the GE trees and their progeny in our forests would be nearly impossible, especially over a long period of time.

Our inability to track the spread of these GE trees means we will not be able to fully monitor for possible adverse impacts and will not be able to recall these GMOs from the wild if needed.

Ecosystem engineering

As well as opening the door to the future use of GE trees in commercial plantations, an approval of Darling 58 could pave the way for other federal approvals to release GMOs into the wild, such as GE insects and GE animals to eliminate diseases and pests. The Indigenous Environmental Network has expressed their concern about what this GE tree means and where it could lead: “Elders and wisdom keepers who have counseled us on the issue of genetic engineering warn this is another attempt to control and commodify the living world. Each step taken in this direction has the potential to further threaten biodiversity already weakened by unchecked natural resource exploitation.”6


Lucy Sharratt is the Coordinator of the Canadian Biotechnology Action Network (CBAN), which brings together 16 groups to research, monitor and raise awareness about issues relating to genetic engineering in food and farming. CBAN is a project on the shared platform of MakeWay Charitable Society.


Watershed Sentinel Dec2020-Jan2021 CoverThis article appears in our December 2020 | January 2021 issue.


  1. Drunen, Stephen & Schutten, Kerry & Bowen, Christine & Boland, Greg & Husband, Brian. (2017). Population dynamics and the influence of blight on American chestnut at its northern range limit: Lessons for conservation. Forest Ecology and Management. 400. 10.1016/j.foreco.2017.06.015.
  2. Canadian Chestnut Council, A Decade of Progress, Accessed October 13, 2020
  3. Petition for Determination of Nonregulated Status for Blight-Resistant Darling 58 American Chestnut -Docket No. APHIS-2020-0030.William A. Powell, State University of New York College of Environmental Science. Submitted January 17, 2020 to the Animal and Plant Health Inspection Service, United States Department of Agriculture. Page 23.
  4. Letter from the Minister of Agriculture and Agri-Food, to Lucy Sharratt, Canadian Biotechnology Action Network. October 2, 2020.
  5. Petition for Determination of Nonregulated Status for Blight-Resistant Darling 58 American Chestnut -Docket No. APHIS-2020-0030.William A. Powell, State University of New York College of Environmental Science. Submitted January 17, 2020 to the Animal and Plant Health Inspection Service, United States Department of Agriculture.
  6. The Campaign to STOP GE Trees. Organizational Sign on. 2020.

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