Genomics of the Blight-Resistant American Chestnut Tree
By MacKenzie Johnston & Madison Hopkyns
Keywords: Genetic engineering, restoration, Indigenous sovereignty, chestnut blight
Summary
As society confronts challenges posed by climate change, pathogens, and species extinction, genetic engineering emerges as a technological solution. The case of the American Chestnut Tree (ACT) illustrates the intersection of these issues and the social contentions that surround it. Following the functional extinction of the ACT in the early 1900s due to a chestnut blight, there have been strong efforts by The American Chestnut Foundation to create a genetically engineered blight tolerant tree and restore the species. Most recently, molecular biologists have isolated the gene oxalate oxidase (OxO) from wheat and integrated it into the ACT genome, which allows it to better withstand the blight.
Restoration of the ACT is happening in Eastern North America, and this project focuses on the Haudenosaunee territory. The use of the genetically engineered tree in this Nation's territory has sparked conversations regarding sovereignty and the future of restoration. There are a variety of viewpoints within the Haudenosaunee community yet most assert that genetic modification does not align with their relations with the natural world. The current discourse of the ACT includes the opinions of the American Chestnut Foundation , molecular biologists, and the Haudenosaunee First Nation. In the following sections we will further describe each group’s perspective, and discuss the opportunities and potential consequences this case presents. |
ECOLOGICAL GENEALOGY
Our Case Study site is not so much a physical location as it is a place in time. It is a junction, where decisions made can result in different but equally complex challenges. For the sake of setting the scene, the area we will be referring to is the historical range of the American Chestnut Tree, Castanea dentata, (ACT). Accounts say the tree was a dominant species within these, making up as much as 50% of forest cover, and was important for nutrient cycling, carbon sequestration, habitat provisioning, and food (Diehm, 2023). Additionally, when the British arrived in the early 19th century, they harvested the species for the height and straight trunks, which were relied on for various building applications. Much of the chestnut’s historical region is also the traditional territory of the Haudenosaunee First Nation, which is now known as Southern Ontario, Quebec, and the state of New York (Childs, 1998). The ACT was abundant in this area in part due to “tribal land management” (Barnhill-Dilling, 2023). This species was culturally vital for the Haudenosaunee Nation who harvested the nuts from the trees and for the animals of which the trees provided habitat.
When the British colonized this area, they recognized a large hunting territory surrounding Lakes Ontario and Erie as Haudenosaunee land, and included it in the Albany Treaty of 1704 (Hill, 2009). As the British were defeated by the U.S colonies they surrendered this land, which was never truly theirs, to the U.S, who granted the Haudenosaunee a small parcel along the Bay of Quinte, Ontario to re-establish their community. The significant treaty negotiations that have taken place since this time are outside the scope of our research, but it is important to note that federal jurisdiction has prevented the Haudenosaunee true sovereignty over their lands (Hill, 2009).
Colonization plays multiple roles in this history, as it was not long after the signing of the Treaty of Albany, that a fungus from Asia, Cryphonectria parasitica, was introduced via a port in New York (Diehm, 2023; Powell, 2019). By this time, settler interactions with the tree had created concentrated stands of it, which allowed the blight to decimate the species, which has no natural resistance to the pathogen. The ACT has been left functionally extinct in its native region. Throughout the last three decades, numerous endeavors have been undertaken to genetically engineer (G.E) the species for blight tolerance. Hybridization with Asian Chestnut Trees, backcrossing, and gene insertion are among the strategies used (Brister, 2017; Powell, 2019). Most recently, and the development we will be focusing on, is the addition of oxalate oxidase-encoding gene (OxO) from the wheat genome. This gene would allow the trees to coexist with the pathogen, which is considered a stable evolutionary relationship (Powell, 2019).
When the British colonized this area, they recognized a large hunting territory surrounding Lakes Ontario and Erie as Haudenosaunee land, and included it in the Albany Treaty of 1704 (Hill, 2009). As the British were defeated by the U.S colonies they surrendered this land, which was never truly theirs, to the U.S, who granted the Haudenosaunee a small parcel along the Bay of Quinte, Ontario to re-establish their community. The significant treaty negotiations that have taken place since this time are outside the scope of our research, but it is important to note that federal jurisdiction has prevented the Haudenosaunee true sovereignty over their lands (Hill, 2009).
Colonization plays multiple roles in this history, as it was not long after the signing of the Treaty of Albany, that a fungus from Asia, Cryphonectria parasitica, was introduced via a port in New York (Diehm, 2023; Powell, 2019). By this time, settler interactions with the tree had created concentrated stands of it, which allowed the blight to decimate the species, which has no natural resistance to the pathogen. The ACT has been left functionally extinct in its native region. Throughout the last three decades, numerous endeavors have been undertaken to genetically engineer (G.E) the species for blight tolerance. Hybridization with Asian Chestnut Trees, backcrossing, and gene insertion are among the strategies used (Brister, 2017; Powell, 2019). Most recently, and the development we will be focusing on, is the addition of oxalate oxidase-encoding gene (OxO) from the wheat genome. This gene would allow the trees to coexist with the pathogen, which is considered a stable evolutionary relationship (Powell, 2019).
Present Tense
There are various viewpoints regarding the current state and prospective trajectory of the ACT. As the species is culturally and economically important to a variety of people, there is an incentive to conserve the species, however, the method of preservation is highly contested. Within the context of this paper, the values of the Haudenosaunee Nation, scientific researchers, and the public must be considered when discussing the restoration of the ACT.
Molecular biologists propose that the most effective mitigation option for this species against prevailing biotic and abiotic threats is genetically engineering “high quality seedlings, defined as trees with identifiable morphological traits e.g., large root collar diameters, tall stem heights, and large root systems”, as explained in the article “Reintroduction of American Chestnut in the National Forest System'' (Schaberg et al., 2014). In 2020, a transgenic American Chestnut became the first G.E tree species developed for restoration purposes. These trees exhibit blight resistance via the addition of the OxO gene. This gene detoxifies oxalic acid produced by the chestnut blight fungus, and could hypothetically prevent lethal cankers on the tree (The American Chestnut Foundation, 2024). This modification will equip the American Chestnut with a higher level of resilience and competitive advantage, enabling it to survive in the environment today.
Researchers believe that pushback to the modification of the tree comes from a place of anti-capitalism, as genetics as a field has been criticized for privatizing and commodifying life (Barnes & Delborne, 2022). Attempting to put these claims to rest, the American Chestnut Foundation stated that the genetic material of the chestnut tree will never be patented, and the G.E is being done for restoration alone. However, this point of contention is not the only sticking point in the debate.
Within the Haudenosaunee Nation, there are varying degrees of opposition to the genetic engineering of this species. Community members point to language as a point of restriction. There is nothing in their language to describe genetic modifications, so it is possible exploring new words could help connect to the tree. The article by Barnhill-Dilling describes this by saying that “perhaps this new tree will generate new stories and new cultural practices. The world is always changing. And as we seek solutions to address some of the wicked problems facing our planet, we also want to think about what new stories these solutions are growing” (2023).
Due to the recent genetic engineering of the American Chestnut species, some Indigenous environmental leaders are calling the ACT a new tree, rather than a restored tree. Traditionally, it has been used medicinally, but some elders say they would not use the new tree for these purposes because they have not had time to build a relationship with it (Barnhill-Dilling, 2019). Others are confused about why the American Chestnut was chosen over other trees. We found mixed feelings about the importance of the tree to the Haudenosaunee people, with some greatly missing its presence on the land, and others who don’t consider it to be a cultural keystone species. It is possible that the tree was more valuable to settlers than it was to Indigenous people, which is why the push to restore it has been largely one-sided (Barnhill-Dilling, 2019).
Meeting genetic engineering with open minds is not in the majority for Haudenosaunee community members. In a study conducted for New York State University regarding the future of the Nation's relationship with GE trees, the prevailing sentiment emerged that GE trees do not resonate with their worldview. One Haudenosaunee participant articulated “just because we can doesn’t mean that we should” (Barnhill-Dilling et al., 2019). The concept of G.E species is perceived as beyond the scope of humanity's role within the ecosystem, a sentiment not aligned with the wishes of many Haudenosaunee elders. Unfortunately, they have not felt like their thoughts are valued in this discussion, despite the trees being designed to breed with the existing population across their territory. The community feels that they are “invited to accept, but cannot decline” (Diehm, 2023).
Molecular biologists propose that the most effective mitigation option for this species against prevailing biotic and abiotic threats is genetically engineering “high quality seedlings, defined as trees with identifiable morphological traits e.g., large root collar diameters, tall stem heights, and large root systems”, as explained in the article “Reintroduction of American Chestnut in the National Forest System'' (Schaberg et al., 2014). In 2020, a transgenic American Chestnut became the first G.E tree species developed for restoration purposes. These trees exhibit blight resistance via the addition of the OxO gene. This gene detoxifies oxalic acid produced by the chestnut blight fungus, and could hypothetically prevent lethal cankers on the tree (The American Chestnut Foundation, 2024). This modification will equip the American Chestnut with a higher level of resilience and competitive advantage, enabling it to survive in the environment today.
Researchers believe that pushback to the modification of the tree comes from a place of anti-capitalism, as genetics as a field has been criticized for privatizing and commodifying life (Barnes & Delborne, 2022). Attempting to put these claims to rest, the American Chestnut Foundation stated that the genetic material of the chestnut tree will never be patented, and the G.E is being done for restoration alone. However, this point of contention is not the only sticking point in the debate.
Within the Haudenosaunee Nation, there are varying degrees of opposition to the genetic engineering of this species. Community members point to language as a point of restriction. There is nothing in their language to describe genetic modifications, so it is possible exploring new words could help connect to the tree. The article by Barnhill-Dilling describes this by saying that “perhaps this new tree will generate new stories and new cultural practices. The world is always changing. And as we seek solutions to address some of the wicked problems facing our planet, we also want to think about what new stories these solutions are growing” (2023).
Due to the recent genetic engineering of the American Chestnut species, some Indigenous environmental leaders are calling the ACT a new tree, rather than a restored tree. Traditionally, it has been used medicinally, but some elders say they would not use the new tree for these purposes because they have not had time to build a relationship with it (Barnhill-Dilling, 2019). Others are confused about why the American Chestnut was chosen over other trees. We found mixed feelings about the importance of the tree to the Haudenosaunee people, with some greatly missing its presence on the land, and others who don’t consider it to be a cultural keystone species. It is possible that the tree was more valuable to settlers than it was to Indigenous people, which is why the push to restore it has been largely one-sided (Barnhill-Dilling, 2019).
Meeting genetic engineering with open minds is not in the majority for Haudenosaunee community members. In a study conducted for New York State University regarding the future of the Nation's relationship with GE trees, the prevailing sentiment emerged that GE trees do not resonate with their worldview. One Haudenosaunee participant articulated “just because we can doesn’t mean that we should” (Barnhill-Dilling et al., 2019). The concept of G.E species is perceived as beyond the scope of humanity's role within the ecosystem, a sentiment not aligned with the wishes of many Haudenosaunee elders. Unfortunately, they have not felt like their thoughts are valued in this discussion, despite the trees being designed to breed with the existing population across their territory. The community feels that they are “invited to accept, but cannot decline” (Diehm, 2023).
FUTURE TRAJECTORIES
In response to the rapid decline of the American Chestnut, genetic engineering may offer a contemporary solution aimed at enhancing species resilience and enabling them to better withstand environmental shifts. We are at a critical point where the debate is ongoing, but the experimental trees are actively being tested, planted, and designed to interbreed with surrounding populations. In addition, pathogens have enhanced evolutionary abilities that allow them to quickly overcome defenses put up by hosts; the only response to this is to further modify the genome (Diehm, 2023). This brings up two interesting trajectories that will be explored in this section.
Meeting natural evolution with further genetic modification exposes a future of restoration where humans have to manually control species interactions. This shows elements of a designed ecosystem as it required intensive intervention to create, while holding a specific outcome in mind (Higgs, 2016). In this case, that outcome is resistance to the blight and the restoration of an extinct species. This presents the problem of who decides which ecosystems should be designed to succeed. Is it those with the loudest voices, or those with the deepest pockets? It can be seen through the G.E of the ACT that Indigenous positions are already being overlooked, which is a troublesome precedent to set early on.
In order for Haudenosaunee worldviews to be meaningfully integrated into the conversation going forward, Barnhill-Dilling says we must prioritize the Nation’s sovereignty over its land. Thus far they have merely been updated on decisions, rather than valued members of the conversation. This would include recognition of their governance systems, and a greater awareness about the consequences of treaties.
Perhaps most concerningly, this provokes a line of thinking wherein we can continue to modify species to deal with inherently anthropogenic pressures. This transfers the burden of adaptation onto species, rather than modifying human activities to have less of an impact (Diehm, 2023). If we do not question the societal risks of these actions now, it is likely that we will continue to modify organisms to withstand the pressures we continue to create. Overall the case of the ACT sheds light on the complex challenges unfolding regarding decision making, land sovereignty and changing natures.
Meeting natural evolution with further genetic modification exposes a future of restoration where humans have to manually control species interactions. This shows elements of a designed ecosystem as it required intensive intervention to create, while holding a specific outcome in mind (Higgs, 2016). In this case, that outcome is resistance to the blight and the restoration of an extinct species. This presents the problem of who decides which ecosystems should be designed to succeed. Is it those with the loudest voices, or those with the deepest pockets? It can be seen through the G.E of the ACT that Indigenous positions are already being overlooked, which is a troublesome precedent to set early on.
In order for Haudenosaunee worldviews to be meaningfully integrated into the conversation going forward, Barnhill-Dilling says we must prioritize the Nation’s sovereignty over its land. Thus far they have merely been updated on decisions, rather than valued members of the conversation. This would include recognition of their governance systems, and a greater awareness about the consequences of treaties.
Perhaps most concerningly, this provokes a line of thinking wherein we can continue to modify species to deal with inherently anthropogenic pressures. This transfers the burden of adaptation onto species, rather than modifying human activities to have less of an impact (Diehm, 2023). If we do not question the societal risks of these actions now, it is likely that we will continue to modify organisms to withstand the pressures we continue to create. Overall the case of the ACT sheds light on the complex challenges unfolding regarding decision making, land sovereignty and changing natures.
References
Barnes, J. C., & Delborne, J. A. (2022). The politics of genetic technoscience for conservation: The case of blight-resistant American chestnut. Environment and Planning. E, Nature and Space (Print), 5(3), 1518–1540. https://doi.org/10.1177/25148486211024910
Barnhill-Dilling, K. (2023). [YouTube] Wolfpack Solutions. Retrieved from https://www.youtube.com/watch?v=dCbgooseDac
Barnhill-Dilling, S. K., & Delborne, J. A. (2019). The genetically engineered American chestnut tree as opportunity for reciprocal restoration in Haudenosaunee communities. Biological Conservation, 232, 1–7. https://doi.org/10.1016/j.biocon.2019.01.018
Brister, E. (2017). Genome fidelity and the American chestnut. Issues in Science and Technology 33(4)
Childs, J. B. (1998). Transcommunality: From the Politics of Conversion to the Ethics of Respect in the Context of Cultural Diversity — Learning from Native American Philosophies with a Focus on the Haudenosaunee. Social Justice (San Francisco, Calif.), 25(4 (74)), 143–169.
Diehm, C. (2023). American Chestnut Restoration: Accommodating Others or Scaling Up? Ethics, Policy & Environment, 26(1), 69–85. https://doi.org/10.1080/21550085.2022.2133945
Higgs, E. (2016) Novel and designed ecosystems. Restoration Ecology. Retrieved from https://onlinelibrary-wiley-com.ezproxy.library.uvic.ca/doi/full/10.1111/rec.12410
Hill, S. M. (2009). Conducting Haudenosaunee Historical Research from Home: In the Shadow of the Six Nations-Caledonia Reclamation. American Indian Quarterly, 33(4), 479–498. https://doi.org/10.1353/aiq.2009.a362022
Powell, W. A., Newhouse, A. E., & Coffey, V. (2019). Developing blight-tolerant American chestnut trees. Plant Physiology, 179(1), 1–6.
The American Chestnut Foundation. (2024). Rescue and Restoration of the American Chestnut. Retrieved from https://tacf.org/darling-58/
Schaberg, P. Pinchot, C & Casey, D. (2014) Reintroduction of American Chestnuts in the National Forest System. Journal of Forestry. Retrieved from: https://www.academia.edu/22953036/Reintroduction_of_American_Chestnut_in_the_Nat ional_Forest_System
Barnhill-Dilling, K. (2023). [YouTube] Wolfpack Solutions. Retrieved from https://www.youtube.com/watch?v=dCbgooseDac
Barnhill-Dilling, S. K., & Delborne, J. A. (2019). The genetically engineered American chestnut tree as opportunity for reciprocal restoration in Haudenosaunee communities. Biological Conservation, 232, 1–7. https://doi.org/10.1016/j.biocon.2019.01.018
Brister, E. (2017). Genome fidelity and the American chestnut. Issues in Science and Technology 33(4)
Childs, J. B. (1998). Transcommunality: From the Politics of Conversion to the Ethics of Respect in the Context of Cultural Diversity — Learning from Native American Philosophies with a Focus on the Haudenosaunee. Social Justice (San Francisco, Calif.), 25(4 (74)), 143–169.
Diehm, C. (2023). American Chestnut Restoration: Accommodating Others or Scaling Up? Ethics, Policy & Environment, 26(1), 69–85. https://doi.org/10.1080/21550085.2022.2133945
Higgs, E. (2016) Novel and designed ecosystems. Restoration Ecology. Retrieved from https://onlinelibrary-wiley-com.ezproxy.library.uvic.ca/doi/full/10.1111/rec.12410
Hill, S. M. (2009). Conducting Haudenosaunee Historical Research from Home: In the Shadow of the Six Nations-Caledonia Reclamation. American Indian Quarterly, 33(4), 479–498. https://doi.org/10.1353/aiq.2009.a362022
Powell, W. A., Newhouse, A. E., & Coffey, V. (2019). Developing blight-tolerant American chestnut trees. Plant Physiology, 179(1), 1–6.
The American Chestnut Foundation. (2024). Rescue and Restoration of the American Chestnut. Retrieved from https://tacf.org/darling-58/
Schaberg, P. Pinchot, C & Casey, D. (2014) Reintroduction of American Chestnuts in the National Forest System. Journal of Forestry. Retrieved from: https://www.academia.edu/22953036/Reintroduction_of_American_Chestnut_in_the_Nat ional_Forest_System