By Anne Petermann, Executive Director, Global Justice Ecology Project

March 26, 2025

Introduction

Genetically engineered (GE) trees are an untested and unpredictable technology that threatens not only the biodiversity of our forests but also the ecosystems that depend on them. The case of the genetically engineered American chestnut tree, particularly the Darling 58 (D58), offers a stark example of the dangers associated with the introduction of genetically modified organisms (GMOs) into our natural environments. The failed attempt to restore the American chestnut through genetic engineering raises critical concerns about the potential consequences of these interventions, which are based on insufficient research and reckless optimism. This testimony aims to illustrate the risks of GE trees and the lessons we must learn from the D58 debacle.

The American Chestnut Tree and the Promise of Genetic Engineering

The American chestnut tree was once a keystone species in the eastern U.S. forests, providing food and shelter for countless species. However, the chestnut blight, introduced from Asian chestnut species, along with overlogging, decimated the population in the early 20th century. Over the decades, various efforts have been made to restore the American chestnut. These efforts include both traditional breeding programs, such as those pursued by the American Chestnut Cooperators Foundation (ACCF) and the American Chestnut Foundation (TACF), and the more controversial path of genetic engineering, championed by researchers at the SUNY College of Environmental Science and Forestry (ESF).

The DARLING 58 (D58) is a genetically engineered variant of the American chestnut, created by inserting a wheat gene that enables the tree to produce Oxalate Oxidase (OXO), an enzyme that neutralizes the acid produced by the blight fungus. This would theoretically make the chestnut resistant to the disease that has all but wiped it out. However, this intervention came with insufficient testing that failed to consider long-term ecological consequences.

Failure of the Darling 58 and the Risks of Unregulated GE Trees

The 2020 petition to the US Department of Agriculture (USDA) requesting deregulation of the D58 for unmonitored release into the wild forests of the eastern U.S. was based on three years of field trials. This short testing period is grossly inadequate for a tree species like the American chestnut, which can live for hundreds of years and does not reach maturity until 20 or more years of growth. The rushed deregulation process to allow the unregulated release of D58 into forests—despite the fact that the trees had not even been tested for their full life cycle—demonstrates a lack of foresight and scientific rigor.

In the fall of 2023, the D58 trees began to fail. They became stunted, lost their resistance to the chestnut blight, and in many cases, died outright. This failure surprised even the researchers, leading to a rift between the institutions involved in the project. The rapid demise of the D58 underscores the unpredictable nature of genetic engineering, especially when applied to complex, long-lived organisms like trees. Moreover, these failures reveal a dangerous lack of understanding of how genetically engineered traits behave in natural environments.

Unanswered Questions and the Dangers of Premature Release

The issues with the D58 chestnut tree have not only raised concerns about its viability as a restoration tool but also about the ethical and ecological implications of releasing genetically modified organisms into the wild. If the D58 had been deregulated and widely distributed, its genetically modified pollen could have contaminated the remaining wild American chestnut populations, leading to irreversible genetic damage and ecological changes.

The regulatory agencies, including the USDA Animal and Plant Health Inspection Service (APHIS), have admitted that they lack the expertise and policies to properly evaluate the potential risks of releasing GE trees into wild forests. As one researcher noted during a public webinar, the regulatory review process for GE trees is still in its infancy, and agencies have no clear framework for assessing the long-term ecological impacts. The D58 failure illustrates the profound dangers of releasing genetically engineered trees into the environment without adequate safeguards, testing, or understanding of their potential to disrupt ecosystems.

The Profit Motive and the Ethics of Genetic Engineering in Forests

The push for genetically engineered trees is not just a matter of ecological restoration; it is also driven by profit. The creation of GE American chestnuts has attracted the attention of corporations seeking to profit from the sale of these modified trees. In 2022, researchers at ESF began discussions with American Castanea, a company looking to capitalize on the commercialization of the GE chestnut. This move underscores the underlying financial interests behind the GE tree project and raises concerns about the commercialization of GE trees for private gain and the risks they pose to public resources.

Genetically engineering trees is not about preserving or restoring biodiversity; it is about producing trees that are easier to manage and profit from, whether for biofuels, carbon offsets, timber, or other industrial applications. The notion that GE trees can be used for “forest health” is misleading; these trees are designed to serve industrial and corporate interests, not the health of the environment.

Conclusion: A Call for Caution and Accountability

The failure of the D58 GE chestnut tree is a cautionary tale about the dangers of genetically engineering trees and releasing them into the environment without thorough, long-term testing.

The rush to deregulate these trees, based on limited and flawed research, could have led to catastrophic consequences for the remaining American chestnut population and the ecosystems that depend on it.

We must learn from this failure and demand that any future genetic engineering of trees be approached with caution, transparency, and rigorous scientific testing. We must ensure that the interests of corporations do not take precedence over the health of our forests and the biodiversity they support. The stakes are too high, and the consequences of failure are too great, to allow the unregulated release of genetically modified trees into our natural environment.

The public trust in scientific research, particularly in the field of genetic engineering, must be earned through transparency, rigorous testing, and accountability. As we move forward, we must protect our forests from becoming laboratories for unproven and potentially harmful technologies. We owe it to future generations to ensure that we make decisions that prioritize the health of our ecosystems over profit and expediency.

Thank you for your time and consideration.

Anne Petermann
Executive Director, Global Justice Ecology Project
International Coordinator, Campaign to STOP Genetically Engineered Trees
an**@******************gy.org
716-364-1188