Scientists have cracked the genetic codes of California’s tallest trees — coastal redwoods and giant sequoias — in an effort to help researchers study the genetic diversity of the state’s forests and shield them from the ravages of climate change.
The collaborative effort, dubbed the Redwood Genome Project, involved a team of scientists from the University of California, Davis, Johns Hopkins University, and Save the Redwoods League. Researchers announced the full sequencing of the colossal conifers’ genome on April 23.
The discovery is being touted as a breakthrough, enabling scientists to identify which ancient groves boast the most genetic diversity. The data will also allow researchers and forest managers to identify which trees are suited to survive higher temperatures and new environments amid volatile changes to our climate.
“Genetic diversity is the raw material upon which evolution works,” said David Neale, a plant scientist at UC Davis and the lead researcher for the project. “With that, populations can change their genetic components over time to respond to different things in the environment. If everything is identical, genetically, you have no ability to change in the face of new situations.”
Neale hopes to harness the sequencing data to create something akin to 23andme, a genetic tool that lets people learn about their ancestry and any potential health risks in exchange for a sample of their saliva. He said the Redwood Genome Project resembles the race to cure diseases like sickle cell anemia after the human genome was sequenced in 2000.
“It’s the same as it would be for almost anything, including the human genome,” said Neale. “Without sequencing the genome, you know there’s a genetic component but you don’t know what’s there and how it works. Until you do that, you can’t begin to develop applied technologies around the genetics of an individual organism.
“The (genetic code) is essentially a parts list,” he added.
Funded by Save the Redwoods League, the five-year, $2.6 million project kicked off in 2017. To unravel the genetic mysteries of California’s primeval residents, the scientists used a supercomputer to analyze samples from a coast redwood tree in Butano State Park and a giant sequoia tree from Sequoia Kings Canyon National Park, east of Fresno.
With 27 billion base pairs of DNA, the coast redwood is the second-largest genome ever sequenced. It is second only to the axolotl, a North American salamander with the ability to regenerate limbs and regrow internal organs.
Emily Burns, director of science for Save the Redwoods League, said that the project will provide a framework for future conservation efforts. Over the past 150 years, loggers have wiped out about 95 percent of California’s old-growth redwoods, along with a third of the giant sequoias.
“We really have some fundamental questions about how the natural diversity of those forests have changed,” she said. “It’s the uniqueness of trees in a given population that gives a forest the resiliency to (thrive) during future changes.”
Next, the researchers will collect more than 1,000 samples from both species across the California coast. Burns said that the scientists will work to identify which trees have encoded traits that make them resilient to wildfires or drought. She believes the discovery will soon usher in a renaissance of redwood research.
“At first, we’ll learn only basic information about drought stress or fire tolerance, for example, that might correlate with the genes of both these species,” said Burns. “But, over time, I think it will lead to other, new areas of research.”
“The discovery begins now,” added Neale. “Cures for all kinds of things (in humans) are being developed, but that’s only because we sequenced the human genome. We’re doing the same thing for redwoods. That’s what’s fundamentally important in this moment — that a foundational resource has been developed.”