Sarah Gibbens is a staff writer who specializes
in environmental stories. For the December 2021
issue she wrote about a scientific quest to
resurrect the smell of an extinct flower.Environmental Science and Forestry in Syra-
cuse, New York, began that quest, using what
was then emerging technology. Powell says it
was like having to “build a boat before we went
fishing. We just started testing genes.”
His eureka moment came when he learned
of a wheat gene that enhanced pathogen resis-
tance in tomatoes. The gene produces oxa-
late oxidase—OxO for short—an enzyme that
breaks down the acid produced by the blight
fungus, rendering it harmless. By 2014 May-
nard and Powell had successfully added this
wheat gene to the chestnut’s genome. They
christened the modified tree Darling 58, after
Herb Darling, an engineer and avid supporter
of their work. Trees grown in test plots at
Syracuse proved tolerant of the blight.
Chestnut fans wanted to know when they
could get Darling 58. Eight years later, they’re
still waiting.
Powell is confident Darling 58 is safe, but
transgenic trees inspire a fear of the unknown.
Who can grow genetically modified crops and
where they can be grown are tightly regulated in
the United States. Powell and his colleagues have
asked the Department of Agriculture, the Food
and Drug Administration, and the Environmen-
tal Protection Agency to deregulate Darling 58,
affording it the status of a nonmodified tree. It’s
the first time these agencies have grappled with
such a request—to release a genetically modified
tree into the wild—and it would set a precedent
for other plant species.
“Once these are out in the forest, there’s no
calling them back. There’s no way to reverse it,”
says Anne Petermann, executive director of the
Global Justice Ecology Project. Some Indigenous
activists also are concerned the trees will violate
their right to keep genetically modified organ-
isms, or GMOs, off their land.D
ESPITE THESE FEARS, scientists say
genetic engineering is a powerful
tool for keeping forest ecosys-
tems intact. At Purdue University,
researchers have been studying
ways to genetically modify ash trees to fend
off the emerald ash borer, a highly destructive
beetle. In Canada, scientists have developed
a genetically modified poplar that wards off
spruce budworm. And at Powell’s lab in Syra-
cuse, scientists are investigating new genes to
embed in elm and chinquapin trees.
For fans of the American chestnut, like Mann,
whose parents told stories of the tree’s demise
and whose grandchildren may see its return,
restoring the chestnut would be proof that envi-
ronmental wrongs can be righted. At his home in
Kentucky, Mann engages in what he calls “chest-
nut evangelism.” He says he’ll preach the value
of chestnuts “until I start drooling.”
“A lot of people don’t even know all this death
and destruction has been unleashed in our
forest,” he says. “I think we have no right to just
stand by and let all this disappear.” jA lab worker removes
the spiky green bur
from chestnuts polli-
nated with transgenic
pollen. With each gen-
eration of genetically
modified trees, scien-
tists get closer to the
day when American
chestnuts may once
again thrive in the wild.
AMY TOENSINGFIXING FORESTS 137