These trees once ruled the canopies of much of Appalachia, with billions of mature American chestnut trees that towered in leafy forests from Maine to Mississippi. But around the beginning of the 20th century, an exotic fungus nearly drove the tree out of existence. Today, they still sprout in the wild but rarely reach maturity. Outside of growers’ orchards, scientists say, the tree is “functionally extinct.”

[Kyra] LoPiccolo and other researchers at SUNY ESF are growing American chestnut trees in the fields of Syracuse that can withstand that infection: Half of the nuts produced with the genetically engineered pollen will carry DNA meant to fight the blight. The researchers are now ready to sow the seeds in the wild, pushing to become the first in the United States to use genetic engineering to bring a forest tree back to its former glory.

But first, the project is seeking approval not only from three federal agencies but also from chestnut aficionados concerned about altering the genome of a beloved tree.