Boise State University researchers assemble first complete sagebrush genome sequence
Project is a step toward preserving the sagebrush sea of the Western U.S. in the face of climate change
Researchers at Boise State University have assembled the first sagebrush genome sequence, opening many doors to help protect the sagebrush sea of the American West from risks like drought and wildfire.
But more than saving sagebrush itself, this milestone allows for further preservation of entire ecosystems. Animals such as sage grouse, pygmy rabbits, pronghorns and several other species depend on the habitat of sagebrush to survive.
“I’m from Switzerland and when I came here, (to America), I didn’t know much about sagebrush, to be honest,” Boise State assistant professor Sven Buerki said. “I really started falling in love with the species and how amazing it is in this habitat.”
Sagebrush genetics are far more complex than the human genome, which was mapped nearly 20 years ago, and is 2.3 times the size, according to a release from Boise State. Buerki collaborated with fellow Genes by Environment: Modeling-Mechanisms-Mapping, or GEM3, program researchers to propagate identical specimens of sagebrush until they had enough biomass to extract the DNA needed without destroying any plants.
The larger genome allows for more genetic variation, including in nutrient levels and flavor, but it also packs thousands, maybe millions, of years of genetic history.
Sagebrush history goes back to the Ice Age
Jennifer Forbey, a professor in Boise State’s Department of Biological Sciences, said animals won’t eat just any sagebrush and that they look for the most nutritious stands as they survive the winter months.
“I think about foodscapes, and what those landscapes of food look like for animals trying to get a meal so they can survive, reproduce and grow each year,” Forbey said. “One thing that’s really interesting that few people know about artemisia, the sagebrush, is that it’s been in our Western landscapes since before the Pleistocene (epoch).”
While the sagebrush seen all across the American West is not the same one that migrated from Asia along with wooly mammoths and other Ice Age creatures, it is the result of generations of adaptations to toughen the plant to the desert environment it now resides in. However, it isn’t able to adapt to everything without help.
The wildfires and droughts seen in recent years as a result of climate change are taking a toll on sagebrush populations. Conservation efforts, which include entities like the Bureau of Land Management spreading seeds in damaged habitats and hope they grow, have proven ineffective. Through Buerki and postdoctoral researcher associate Anthony Melton’s work, the foundation has been laid to improve sagebrush’s resilience to fire and drought while also predicting its palatability for wildlife.
With the first genome sequence of the most widespread species of sagebrush created, it will enable researchers to create the genomes of other species of sagebrush. Melton collected samples from several populations of sagebrush across the Western U.S.
“Sagebrush has a very slow growth,” Buerki said. “And that’s the thing, as fire comes more frequently and gets rid of all the seed banks. That is a problem that everybody is having and, at the moment, what they do is they ask people all over the range to collect seeds and agencies like BLM reseed those areas. But that doesn’t really work.”
So instead, Buerki and Melton plan to use their new biotechnology to develop new tools that will help spread sagebrush that can withstand fires better.
Forbey said animals aren’t the only beings that rely on sagebrush – other plants do as well. The chemicals that sagebrush can release into the soil or air send signals to other plants, such as letting other flora know herbivores are near, Forbey said, making the plant a “chemical chameleon.”
Forbey said sagebrush descends from an Asian plant commonly known as wormwood, specifically Artemisia annua, which played a key role in an anti-malarial drug primarily developed by Youyou Tu. She was awarded the 2015 Nobel Peace Prize for Psychology or Medicine.
Native Americans also found uses for sagebrush in their health care and ceremonies. A paper authored by Bruce Kelley in 1992 claimed some Navajo tribe members react differently to certain cancer treating drugs as a result of the use of sagebrush during Lifeway chants.
“All of these people published this amazing account of the sagebrush steppe when they’ve shown it is one of the most imperiled ecosystems worldwide,” Buerki said. “The sad part is places like Madagascar, all of those places that are really suffering, this is in our backyard. So we ought to do something. People need to realize the uniqueness and the beauty of this habitat.”