Tree research and survival viable without genetic engineering

 

Chestnut trees, which have been bountiful along the East Coast, are being devastated by blight fungus. In the fall edition of the Sierra Atlantic, an article (“The mighty American Chestnut: New York conservationists lead epic tree restoration effort”) discussed both traditional and biotechnology efforts to save these majestic trees.

Unfortunately, the article could have given the impression that the Sierra Club approves the release of genetically engineered organisms into the environment.  According to Sierra Club’s policy, “Based on the precautionary principle, the Sierra Club calls for a ban on the propagation and release of all genetically engineered organisms, including field crops, orchard and forest trees.”

Genetic engineering (GE) is a new technology that, unlike traditional breeding methods, allows the transfer of genetic material from one organism into a host organism of an unrelated species, thus bypassing the natural reproductive barriers between species. The genetic manipulation resulting from genes inserted by genetic engineering cannot be recalled and the altered characteristics will be passed on to future generations and continue to be reproduced in the environment.

A May 30, 2015 article in the New Scientist reveals that the first GE chestnut was planted in 2006, and there are now over 1,000 GE chestnut trees growing at various test plots in New York. Charles Maynard, of the State University of New York, stated, “We hope to obtain regulatory approval for trees to be grown outside permitted plots within three to five years.”

In the documentary A Silent Forest: The Growing Threat, Genetically Engineered Trees, award-winning geneticist Dr. David Suzuki discussed how GE trees may adversely impact ecological systems.  As Dr. Suzuki explains, the problem with genetic engineering has to do with the fact that GE plants and animals are created using horizontal gene transfer, as contrasted with vertical gene transfer, which is the mechanism in natural reproduction. Vertical gene transfer is the transmission of genes from the parent generation to offspring via sexual or asexual reproduction. By contrast, horizontal gene transfer involves injecting a gene from one species into a completely different species, which yields unexpected results.  According to Dr. Suzuki, the assumption that the principles of vertical inheritance can be applied to horizontal inheritance is flawed and is “just lousy science.”

“Forests are already under tremendous pressure from climate change and human interaction,” says Dr. Ricarda Steinbrecher, who has a PhD in molecular genetics. “Compared to crops that have been cultivated for thousands of years, trees are wild. If a GE trait enters a forest species, the implications could be absolutely horrendous. We could see the ecological system weaken and collapse.”

According to Dr. Steinbrecher, “You cannot design a biological system that’s 100 percent foolproof.” Data backs her up.  According to the United Nations Food and Agriculture Organization, even at a 95 percent success rate, it is nearly impossible to control gene flow through pollen and seed dispersal.

The good news is that the American chestnut still exists throughout the forests of the Eastern U.S.  Many of the trees that were killed off by the blight resprouted from the stumps. Many of these have survived to the point where they are producing chestnuts that are being harvested by people and feeding wildlife. There is also active work being undertaken to identify and breed naturally resistant wild American chestnut trees. The Sierra Club approves and encourages these non-GE methods being used to bring back the chestnut.