When we talk about an oldchestnut, we usually mean a familiar storysometimes one thatsbeen told so often thatithas become stale, but also possibly one thats ready and reliable.

Either way, the phrase suggests a kind of sturdiness and permanence, perhaps like an old chestnut tree thats always there.

Except that these days, theresalmostno such thing as an old chestnut treeinthe easternUnited States. Virtually all ofthemhave succumbed to a deadly disease. By some estimates, four billion have perished. The only thing that has the potential to bring them back is biotechnology.

Eight years ago, I wrote about the plight of the chestnut treesin acolumnfor the Global Farmer Network.I described chestnuts as an essential part of Italian-American culture: In my family, we always roasted them for Christmas and on other holidays.The wood from the trees also made beautiful furniture.Im no woodworker, but my grandfather was and chestnut trees are an excellent source of hardwood.

A generation or two ago, chestnut treeswere a common feature of the American landscape. They would grow big and tall, with thick trunks and branches that could reach a hundred feet into the air.The trees that produced the delicious nuts and gorgeous wood grew in the wild as well as under cultivation.

Then came the blight. A fungus from Asia swept through our continents population of chestnuts.Today, its almost impossible to find chestnut trees.Several years ago,I tried to grow a couple near my house in New Jersey. One died immediately. The other lasted a few years and then it died, too.Even when we care for them, we cant seem to keep them alive.

My column pointed out thedire challenges facing the chestnut tree, but also expressed hope that modern science might find a solution.

Today, it looks like we may have one.Scientistshave discovered a fungus-fighting enzyme that occurs in all grain crops as well as some fruits. Through an initiative sponsored by theAmerican Chestnut Research and Restoration Projectatthe State University of New York, theyve figured out how to take a gene that produces this enzyme from bread wheat and transplant it into chestnut trees.

Thistechnique is calledgenetic modificationand its the same onethat has become a staple of modern food production, helping farmers fight weeds and pests and allowing them to grow more food on less landthan ever before. We call thesecropsGMOs,for genetically modified organisms,but it may make more senseto introduce a companion name:GROs, as in genetically rescued organisms.

I learned this termfrom Hank Campbell, who wrote anop-edabout chestnuts in the Wall Street Journal in June. His own website, Science 2.0, also hascoveredthe plight of chestnut trees and the ways in which science can save them.

GROs have been with us for a while.Theyve alreadysavedHawaiis papaya industry from the ring-spot virus. Nowwere applying this same method to another plant whose situation has become desperate.

For those who worry that theres something unnatural aboutthis approach, Campbelloffersthis useful way of thinking aboutGRO chestnuts: What could be more natural than letting nature resist nature? It is 99.999 percent identical to wild American chestnuts, except four billion of these wont die.

That sounds like a good deal to me. We might be wise to think about othertrees and plantsthatcouldbecome GROs.Elm trees may be candidates.Dutch elm disease, a fungus spread by bark beetles, has ravaged them as well. This afflictions acronym says it all: DED.

I dont know about you, but I prefer GRO trees to DED ones.

We can continue to watch chestnut trees and other species vanish, or we can choose adifferentfuture. Thankfully, the federal government is trying to modernize the regulations that governGROs. In January, President Trump issued an executive order that may spur innovationsand make it easier for scientists to defeat diseases and rescue trees.

One day, perhaps, well be able to tell old chestnuts about how we saved the chestnuts.