The chestnut tree was once the dominant tree in forests east of the Mississippi River, but that was before the chestnut blight. First observed at the Bronx Zoo in 1904, the blight destroyed more than 4 billion chestnut trees by the 1940s.
In 1983, a hardy band of plant scientists and volunteers founded the American Chestnut Foundation (TACF) Its aim: to breed blight resistance from the Chinese chestnut tree into the American chestnut tree, while maintaining the American chestnut's characteristics. Beyond that, the group's ultimate goal is to "reestablish the American chestnut's function in its native range."
As the science of genetics advanced, the foundation added a biotechnology program. This aims to endow American chestnuts directly with a gene from wheat called oxalate oxidase, or OxO. The OxO enzyme protects the trees by breaking down the oxalic acid that the blight uses to attack them. Adding just a gene or two to the American chestnut genome would make the trees even more "native" than those back-crossed with Chinese chestnuts.
At the beginning of 2020, TACF petitioned the U.S. Department of Agriculture to give the blight-resistant American chestnut "nonregulated status." This would allow the blight-tolerant bioengineered trees to be planted without restriction. A coalition of anti-biotech activists—The Campaign to STOP GE Trees—is opposing the petition.
Now the venerable Sierra Club is inching toward embracing the TACF's blight-resistant chestnut. The group's response to the TACF's petition gingerly concludes that introducing the blight-resistant chestnut to eastern forests likely presents "no threat to ecosystems" and "provides an environmental benefit." An article in the Sierra Club's magazine shows a similar openness to the idea.
"One of the great ecological tragedies of the last century was the destruction of tens of millions of American chestnut trees through an invasive fungal disease," I noted in my own public comments to the Department of Agriculture. "The development and wide-scale deployment of a new fungus-resistant variety of American chestnut by means of modern biotechnology would go a long way toward reversing this tragedy and restoring the ecological balance of east coast forests."
Disclosure: Over the years, I have from time to time made small contributions in support the TACF. I also wrote a case study on the foundation's work back in 1997 for the Competitive Enterprise Institute.