In the 1800s, the American Chestnut was one of the most important trees in the eastern U.S. 

“It produced this large reliable nut crop every year," said Adriana Del Grosso, the Tree Distribution Manager of the American Chestnut Research and Restoration Project. "That was important for the people of America and also the wildlife. It was a great source of rot-resistant lumber that was used in a variety of ways from furniture building to the construction of structures."

There were almost four billion along the east coast, but they were wiped away largely due to a fungus that came into New York in the 1900s. The nuts were used to feed millions, while the wood was used to build fence posts, flooring and telephone poles.

“Once the fungus gets into the tree it produces toxins that kill the living tissue," said Del Grosso. "The toxin that the fungus produces is called oxalic acid, so when it kills the living tissue the tree can no longer transport water and nutrients.” 

The American Chestnut Project is creating a genetically-engineered fix by using oxalate oxidase, a gene that is found in many plants. 

Hannah Pilkey, the Breeding and Production Manager of the project says oxalate oxidase works when it comes in contact with the oxalate which is the acid secreted by the fungus.

"The gene breaks it down into hydrogen peroxide and carbon dioxide. It’s essentially neutralizing the fungus," she said.

So, how does the gene get transferred? 

“We grow up a bacterium called agrobacterium," Pilkey said. "This bacterium is able to transfer its own DNA into plants and kind of manipulate the plants into producing sugars that will feed this bacterium."

The experts say the oxalate oxidase gene is then fed into the chestnut cells to make the tree resistant to the fungus. Once cells are transformed, the next step is growing the tree.

“We are planning for the first distributions in the fall of 2023, assuming that we have federal regulatory approval," Del Grosso said.