2017 ASHS Annual Conference

The American chestnut (Castanea dentata) was a keystone species of North America, making up over a quarter of the forests east of the Mississippi river. The arrival of Cryphonectria parasitica on Asian chestnut stock in the late 1800s introduced the chestnut blight to the continent, which devastated the chestnut population. The American Chestnut Research and Restoration Project has achieved pure American chestnuts able to withstand the chestnut blight chestnut by inserting the gene for oxalate oxidase into American chestnut embryos. The oxalate oxidase enzyme breaks down the oxalic acid secreted by Cryphonectria parasitica, the tree builds a wound periderm, and the infection is contained as merely a small, superficial canker instead of girdling and eventually killing the tree, allowing both organisms to live communally and reach reproductive maturity; presence of the transgene in resulting offspring also confers full blight resistance. As the American Chestnut Research and Restoration Project nears its goal of a publicly-available, fully blight resistant tree, performing environmental and safety testing and increasing tree production are top priorities. We will present our current findings on how non-target organisms may be affected by the inclusion of a novel transgene in American chestnut.