Has genetic engineering become a tool to help living things adapt to climate change?
CRISPR gene editing creates opportunity for animals and plants, including trees, to help reduce emissions and protect forests from wildfires
|Oct 22, 2020|
Above, Emmanuelle Charpentier speaks at a science festival in 2017. Charpentier and Jennifer A. Doudna were last week awarded the Nobel Prize in Chemistry for the development of the CRISPR/Cas9 genetic scissors, a method for genome editing that the Royal Swedish Academy of Sciences said was about "rewriting the code of life." Photo: Norwegian University of Science and Technology/flickr.
By Gunnar Wetlesen
(Gunnar Wetlesen is a semiconductor veteran who began making chips when integrated circuits had only hundreds of transistors, and he went on to co-found two successful IC companies. The second, VLSI Technology Inc. (VTI), pioneered the present design and foundry model. Gunnar is passionate about science and technology, especially innovations that promote sustainability and address climate change. He is a consultant and adviser with a degree in physics.)
SAN FRANCISCO (Callaway Climate Insights) — The primary focus of fighting climate change has been on reducing greenhouse gases that act like insulation in the atmosphere, raising global temperatures. But while the planet continues to heat up, creatures in the natural world struggle to adapt and wildfires become more prevalent.
Some scientists are suggesting that genetic engineering is a way to accelerate what would normally be an evolutionary response over millennia. Cornell University has published articles on plants and animals that can be adapted to climate change with genetic engineering using the CRISPR gene editing tool.
There is even work on modifying trees to help prevent destructive wildfires, such as the ones we’ve seen in California, Colorado, Australia, Brazil, and the Arctic.
CRISPR is gene editing; a genetic engineering technique in molecular biology by which the genomes of living organisms may be modified. It is based on a simplified version of the antiviral defense system naturally occurring in bacteria combined with a guide RNA so a living cell’s genome can be cut at a specifically desired location, allowing existing genes to be removed and/or new ones added to alter the characteristics of that plant or animal. CRISPR stands for clustered regularly interspaced short palindromic repeats.
Up to the advent of genetic engineering, selective breeding has long been the method to select for or emphasize desirable traits like disease resistance, size, or taste in plants or creating new breeds of animals. CRISPR provides a tool for a new methodology for accelerating genetic selection and making possible new species attributes to counter climate change.
This article from Cornell University describes five ways CRISPR DNA could be used in the modification of plants:
Engineering more robust crops to persist in unfavorable environments
Engineering nitrogen fixation to end dependence on added fertilizers
Engineering hardy produce to prevent food waste, so croplands go further
Engineering plants to prevent methane emissions and fix more carbon
Revolutionizing fundamental plant research with CRISPR
Scientists are already demonstrating how CRISPR can engineer plants that are heat tolerant, drought tolerant and salt tolerant. Scientists are using CRISPR to engineer rice that produces less methane in cultivation and cattle feed that is easier to digest. They’re also working to make crops fix more carbon directly and fix nitrogen as legumes do to reduce reliance on chemical fertilizers and their impacts.
Cornell has also published a list of areas where genetic modification in animal organisms could help them endure climate change:
CRISPR-engineered coral reefs (for improved heat tolerance)
Protecting livestock with CRISPR (for disease resistance)
CRISPRing cows to produce less methane
CRISPR helps animals take the heat (e.g. for shorter hair on cattle)
CRISPR for aquaculture (preparing species for aquaculture)
Heat waves have already killed half of the coral in the Great Barrier Reef. Scientists have been trying to breed coral for improved heat tolerance. They have teamed up to demonstrate, for the first time, that it’s possible to tweak genes in coral using CRISPR.
Climate change will cause weather patterns to shift and the boundaries of some pathogens will shift as a result. Fortunately, scientists are already using CRISPR to engineer disease resistance in several livestock including cows, pigs and chickens.
How much methane a cow produces very much depends on that cow’s genetic makeup. That means that genetic engineering could help shrink the big burpers’ carbon hoofprint.
But unlike with plants, FDA approvals currently require the same process as for medications for animals. There is also consumer opposition, especially in Europe, to genetically modified organism (GMO) foods. And there are scientific concerns about introducing engineered organisms into nature which can impact entire ecosystems dependent on them. This includes genetically engineered fish species that can escape from ocean aquaculture settings and breed with and affect wild fish populations.
Another target for genetic intervention is the impact of climate change on forest wildfires which cause widespread destruction while releasing major amounts of CO₂.
Although the exact quantities are difficult to calculate, scientists estimate that wildfires emitted about 8 billion tons of CO₂ per year for the past 20 years.
In 2017, total global CO2 emissions reached 32.5 billion tons, according to the International Energy Agency, so it is a significant percentage. Can trees be engineered to be more drought tolerant or resistant to parasites and disease and forests replanted in a meaningful timescale?
Genomes of economically important trees species with divergent resistance mechanisms can now be exploited to uncover the mechanistic basis of long-term drought adaptation at the whole plant level. Molecular tree physiology indicates that osmotic adjustment, antioxidative defense and increased water use efficiency are important targets for enhanced drought tolerance at the cellular and tissue level. But testing and seeing the results of such changes may take a considerable time and commitment to implement.
Not all genetic traits in species require genetic engineering or make it impractical at scale. Another way is to naturally select trees for propagation that have greater resistance to beetle infestations that kill nearly entire forests when stressed by climate with them becoming fuel for more intense wildfires.
Scientists in British Columbia found that fire-surviving mature trees in a high elevation forest of whitebark and lodgepole pine were genetically distinct from “general population” trees that were assumed to represent the genetic structure of the population pre-outbreak and without selection by the beetle. These trees should not be clear cut after fires and their seeds should be used for forest re-plantings.
Since climate change impacts are worldwide, there is both need and opportunity for many kinds of efforts to mitigate it. Genetic engineering using CRISPR is an important tool.
We can only hope that new and ongoing research efforts will be meaningful in the time scales currently envisioned to help enable critical plant and animal species to adapt and endure so human populations will not be endangered, too. Unfortunately, we don’t have many decades to find out.