In front of the city hall building in Perth Amboy, New Jersey, there’s a weathered old elm tree that’s seen more than 200 years of American history. Throughout those centuries, it has withstood bouts of Dutch elm disease and poundings from brutal storms like 2012’s Hurricane Sandy.
This winter, U.S. Department of Agriculture (USDA) researchers will take a high-tech approach to ensuring the genetic heritage of that tree—the town’s oldest resident. Under an agreement with the New Jersey Department of Environmental Protection (NJDEP), scientists with USDA’s Agricultural Research Service (ARS) will “cryopreserve” twigs cut from the aging tree’s branches—in essence, storing them in a flash-frozen state for decades and quite possibly, centuries.
The original plan was to cryopreserve the elm’s seeds, notes Christina Walters, a plant physiologist with ARS’s National Laboratory for Genetic Resources Preservation in Fort Collins, Colorado. However, there were no embryos within the seed—probably because there were no other surviving elms nearby to pollinate the flowers.
The elm was planted around 1815 and today is considered a symbol of the coastal town’s strength and ties to both New Jersey’s and the nation’s history. However, officials worried the elm’s advanced age would ultimately make it too hazardous to remain standing. They reached out to ARS in hopes of preserving its genetic and historical legacy.
Since the seed couldn’t be used, Walters’ team decided to try cryopreserving cuttings from the tree’s twigs this winter—with help from a NJDEP crew—when temperatures are at their coldest. This spring, they will also try other approaches to obtaining seed.
To Walters, the technical challenge of cryopreserving the elm is consistent with the laboratory’s overarching mission, which is to safeguard not only important plant genetic resources, but also those of animals and microorganisms.
ARS is the USDA’s principal, intramural scientific research agency.