Tuesday, September 29, 2020

A Call for Support / Transgenic Chestnut

I thought it important to share this with my readers.

Many of you are probably at least vaguely aware of the expectation that American chestnut will be saved from virtual extinction by the work of The American Chestnut Foundation (TACF), a program of backcross breeding to introduce Chinese alleles for blight resistance into the genome of the American chestmut (Castanea dentata). 

This work began in 1983 and followed 60 years of failed breeding efforts by USDA and others. TACF became the “little engine that could,” a small non-profit that has managed to leverage tens of millions of dollars in philanthropy, volunteer labor, scientific collaborations, and state and federal funding toward a goal that had been abandoned as impractical by the 1970s.

Saving American chestnut has always been a goal with wide public appeal – rescuing a cherished element of our natural and cultural history that went missing a century ago. This inspirational goal, combined with confidence that TACF’s science-based program of R&D will succeed, is the leverage that sustains support for the work of the organization. It’s a fragile arrangement, like many worthwhile things, and before success is achieved it will have to be sustained by 50+ years of confidence and enthusiasm from people who themselves may never see the goal realized.

Progress with the breeding program is slower than expected because there are more genes involved in Chinese resistance than originally believed. This work will continue, but attention has broadened to include a transgenic American chestnut created by Bill Powell and Chuck Maynard at SUNY-ESF, the culmination of 30 years of difficult work supported by the NY Chapter of TACF. With legal guidance provided by TACF, SUNY-ESF has applied to USDA-APHIS for permission to use the transgenic tree in restoring American chestnut.

The public comment period on the application to USDA-APHIS ends October 19, and I urge my readers to submit a comment. Commentary from both lay persons and scientists is an important consideration in the approval process.

Here are links to the pertinent information:

1.       The Transgenic American Chestnut Tree FAQ’s

2.       Using Science to Save the American Chestnut Tree

3.       Federal Register: Petition for Determination

This single-gene addition to American chestnut is an ecologically safe modification, and there is no commercial interest in obtaining USDA-APHIS approval for use. This is purely a conservation effort for the best of purposes, to restore a keystone species to its original habitat.

If the application is approved, followed by approvals from EPA and FDA, then many more years will be required to move the gene into diverse, regionally adapted populations for restoration. While that is underway, the original breeding program will continue, and TACF will pursue efforts to identify Chinese resistance genes that could be used for cisgenic transformations.

The rescue of American chestnut is a marathon, and SUNY’s transgenic is simply one more step and not necessarily a complete solution. But for reasons both technical and otherwise, I believe that approval of the transgenic is likely to be critical to the success of TACF’s mission. Moreover, if anti-science arguments can prevent this innocuous application of genetic engineering, then the future is grim not only for American chestnut but also for many other plant species under assault by introduced diseases and insects. When a plant has essentially no native resistance to an introduced pest, then genetic modification can well be the only means of saving it.

Kim C. Steiner | Professor of Forest Biology, Department of Ecosystem Science and Management, and Director, The Arboretum at Penn State

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