The Next Frontier for Biotechnology & the Future of Forestry

My home state is well known for its distance from any large body of water and its flat, open plains and fields. From my front porch, I could see over the river into Iowa on a clear day which was almost 50 miles away. Because of this expansive openness, I saw some of the most beautiful skies and felt some of the coldest wind, all because of a common thread natural to this location. There are very few trees on the plains of Nebraska. Yet it is home to the biggest tree holiday, Arbor Day. I love my home; it was days running barefoot through the pastures or in the mist of the center pivots with my sister where I witnessed the food that fuels much of the population growth from the rich earth around me. However, for my Ph.D., I moved to Georgia where forestry is a major economic asset, a large contrast to the corn state. Forestry is also critical for carbon offsets, building materials, pulp and possibly even biofuel. Despite the obvious importance of trees and forests to us, trees are in the crosshairs of human-induced climate change. Some challenges they face are increased disease and infection, extreme weather events, water limitation and new pest problems.

My Ph.D. research uses a model tree species that is a fast-growing poplar hybrid known as Populus tremula x P. alba INRA 717-1B4, for short 717. Poplar species have long been a candidate feedstock for biomass production and recently for conversion to aviation biofuel. Specifically, my dissertation aims to understand how xylem (woody tissue) preferential sulfate transporter genes impact wood formation and drought response. To tackle this, I use CRISPR-Cas9 technology to edit multiple sulfate transporter genes, rendering them non-functional to the trees. In parallel, I am producing trees that are over-expressing these genes in all tissues. This gives me a wide spectrum of transgenic populations with which to address how the specific sulfate transporters change the tree both at a micro and macro – scale.

My research uses the foundation of genetic modification that began in the late 1990s which lead to the development of Roundup Ready Soybean and Rainbow Papaya, both of which represent major improvements to food production and accessibility. These were both made by the addition of a foreign gene to improve the crop’s ability to survive stressors. This idea of genetic modification is expanding from its main use in food and feed production to other areas. Most interestingly for me is improvements to both natural and plantation forests.

Much like many other genome-edited products, there have been roadblocks and hiccups along the way. Genetic engineering of trees sometimes incites a strong emotional response from people, somewhat like the emotional connection we have to food. The emotional response is rooted in feelings like those I mentioned in my love for my home on the plains. We connect with trees at a deeper level through memories and our desire to preserve those things that feel like home or to preserve the natural environment. Think about how you were first told you could improve your home or environment; you likely planted a tree. I know I did every year of primary school on Arbor Day at our playground with my class of 6.

Ironically, despite our desire to preserve those things like home, we have impacted and changed the environment to the point that those trees we love so fondly may not be there for the next generation to love without biotechnological intervention. For example, I have never seen an American Chestnut (Castanea dentata) on any of my many hikes in the mountains of North Georgia, its native range. This is due to the human introduction of fungal blight (Cryphonectria parasitica) in the 1800s. The American Chestnut was a tree similar in size to the sequoias we love on the west coast of the U.S. today, and it once provided material for building and food and shelter for animals. The State University of New York Environmental School of Forestry (SUNY-ESF) has been developing a genetically engineered blight-tolerant chestnut using transgenic biotechnology with the name Darling for decades. It is tolerant to the blight through the introduction of a gene that detoxifies a chemical produced by the fungus that would normally kill the tree.

The American Chestnut is just one example of the amazing things biotechnology can do for not only us but for our environment. The technology of CRISPR-Cas9 for directed gene editing has only been around for a little over a decade and less so in long-lived species like trees. For my research with this technology, I hope to better understand how long-lived species like trees respond to human-induced stressors like drought. The long-term goal is to be able to have trees that can grow in a complex, stressful environment like what’s predicted in the coming years. These trees could provide habitat during their growth periods, restore depleted soils and eventually be utilized for materials or biofuel production. This is the next frontier of biotechnology and exploration for us as we strive to protect the very things that feel like home, for the betterment of our planet.