To feed about 10 billion people by 2050, using existing land and resources available on the planet, it is necessary to change the system of agriculture and animal husbandry as a whole, scientists believe. In addition, human attempts to feed the Earth’s atmosphere are polluting by heating the planet with methane emissions. What is the way out? Researchers offer CRISPR genome editing technology to address food security and climate change. We tell you how the technology works and what other original ideas scientists have. Spoiler: backpacks to collect animal burps are just the tip of the iceberg.
New strategy to reduce emissions
About 200 countries signed the Paris Agreement in 2016, promising to reduce greenhouse gas emissions in their countries. It is now well known that greenhouse gases emitted by human activities capture heat and heat the Earth’s surface. To reduce emissions, many countries are switching to cleaner forms of energy, such as solar and wind energy, and creating incentives for electric cars.
But the new report proposes a somewhat unexpected strategy to reduce emissions: editing plant and animal genes.
“I think everyone but a few fiction writers underestimated the extent to which the climate will change human activity and the relationship between people and the environment,” said Val Giddings, PhD, senior research fellow at the Foundation for Information Technology and Innovation. This is a non-profit research center that released the report. Speaking during a panel discussion on the report on September 15, Giddings said gene editing can help remove more carbon from the atmosphere, reduce food waste and reduce methane emissions from livestock.
Gene editing by CRISPR method
CRISPR (clustered regularly interspaced short palindromic repeats, regularly arranged in groups) are special loci of bacteria and archaea, consisting of direct repeating sequences, which are separated by unique sequences (spacers). Spacers are borrowed from alien genetic elements that a cell has encountered (bacteriophages, plasmid). RNAs transcribed from CRISPR loci together with associated Cas proteins provide adaptive immunity through complementary binding of RNA to nucleic acids of foreign elements and their subsequent destruction by Cas proteins. However, to date, there is a lot of evidence of CRISPR participation in non-immunity-related processes.
The use of CRISPR-Cas techniques for directed editing of genomes is a promising trend in modern genetic engineering. As of 2016, scientists are widely using approaches based on CRISPR-Cas systems; it is possible that in the future these approaches will be used in medicine to treat inherited diseases.
CRISPR-Cas is also important for targeted drug delivery and release under external exposure, using materials that include DNA sites.
In addition, CRISPR can be used as an advanced tool for editing plant genes and in targeted animal production.
The main difference from GMO
Unlike a GMO, the system works with the natural characteristics of crops and does not introduce new genes into samples. Proponents of CRISPR-Cas also argue that the new biotechnology presents fewer risk factors than GMOs. In general, this process is often compared with traditional crop breeding methods.
Gene editing differs from traditional genetic modification in a key sense: gene editing is aimed at changing the own DNA of a plant or animal. On the contrary, traditional genetic engineering involves mixing the DNA of more than one organism. Scientists hope that this distinction will make genetically modified products more acceptable to consumers who are not satisfied with GMOs.
To feed an estimated 10 billion people by 2050, using existing land and resources, we need to change the agricultural and livestock systems as a whole. The agricultural industry, for example, needs to include editing of the CRISPR genome to improve crop productivity, said Oliver Pipples, CEO of Yield10 Bioscience, a company that is developing new technologies to improve crop yields and food security in the world.
In the context of a changing global climate resulting in more frequent extreme weather events and population growth, there is an urgent need to develop new crop varieties that can withstand adverse weather conditions and yield higher yields on the same plot of land. The challenges to sustainable food production caused by climate change are related to unpredictable and volatile seasonal factors, extreme weather conditions that farmers now face. These include drought, flooding, heat and late or early frosts, all of which can have different impacts even during the same growing season.
As average temperatures rise, farm crops are also at greater risk of disease and insect growth. Using CRISPR can help make crops more resilient to these extreme factors.
How will editing animal and plant genes affect the climate?
One of the ways that gene editing can help the climate is by improving plant biology itself. In particular, it can improve photosynthesis, a process that plants use to convert the energy of sunlight into sugar and oxygen. In this process, plants use carbon dioxide, the most common greenhouse gas. Currently, forests and other terrestrial vegetation remove about 30% of anthropogenic carbon dioxide emissions from the atmosphere during photosynthesis.
More “efficient” plants
When editing genes, plants may potentially delete more. Most plants use between 1 and 2% of light falling on them, but scientists believe that their maximum power is actually about 12%. Gene editing can be used to increase their efficiency so that plants can absorb more carbon from the atmosphere.
Gene editing can also be used to accelerate tree growth and expand the root system of plants – both can increase their ability to absorb carbon. Older, more mature trees in rooted forests capture much more carbon than younger trees, as do plants with deeper and wider roots. However, more research is needed before you can use gene editing in this way because the genetics of plant roots are not yet sufficiently understood.
Gene editing can also help reduce emissions from the agricultural industry, especially in developing countries. While in the United States agriculture accounted for about 10 percent of total greenhouse gas emissions in 2018, transportation was the largest contributor (28 percent), followed by electricity (27 percent), agriculture accounts for a much larger share of emissions in developing countries.
In particular, gene editing can be used to reduce food waste in agriculture. It is estimated that one third of the world’s food is lost or wasted every year, and some of it is lost before it reaches the grocery store. For example, the corn harvest in Iowa could be halved this year because of a prolonged hurricane that “walked” through the state and cut crops in August.
Scientists at Bayer Crop Science are modifying corn genes to reduce crop losses, said Scott Knight, PhD, who leads the company’s gene-editing efforts. Shorter corn – corn that’s closer to the ground – will be more resistant to wind and rain, he said.
In 2019, Bayer introduced low corn obtained with the help of traditional genetic engineering, and recently the company has successfully applied genetic editing to its production. While conventional corn grows from nine to 3.3 meters in height, short corn reaches a maximum of about 2 meters, and it also has a thicker stem to prevent it from being damaged by the wind. Company representatives claim that the farmers with whom they spoke seemed interested in using gene editing to solve problems such as crop failure.
The problem of darkening fruits and vegetables
Gene editing can also be used to prevent food waste that occurs after harvesting. Tons of fruits and vegetables are discarded every year due to darkening and damage, and when discarded, they rot and release methane, which is an even stronger greenhouse gas than carbon dioxide.
In North America alone, about a hundred tons of potatoes are thrown away every year because of damage. Potato processing company J.R. Simplot of Idaho already sells potatoes created with the help of genetic engineering to resist damage and darkening, and now uses genetic editing to implement the technology more effectively.
However, the majority of greenhouse gas emissions in agriculture are from livestock production. Gene editing can be used to force cows to produce less methane. It is known that the amount of methane produced by a cow is also highly dependent on its genetic structure. Gene editing has already been used to create horn-free cattle and cows that have more male offspring. The next may be to create less methane from them. But so far, scientists are also offering less invasive methods.
Attempts of scientists to make meat not so dangerous for the climate
A significant portion of global greenhouse gas emissions is associated with methane, a gas that is produced by livestock activities. How do scientists try to minimize damage to the Earth’s atmosphere?
Researchers at AgResearch are wondering if fighting germs in cows’ intestines can help save the planet from climate change.
Now in the stomachs of experimental cows, there is an experiment that could potentially change the planet. They were vaccinated against certain intestinal germs that produce methane when animals digest food. Methane is one of the most disgusting greenhouse gases, which about 25 times retains heat more than carbon dioxide.
AgResearch aims to develop this vaccine along with other antimethane methods so that people can continue to eat meat and dairy products while reducing the environmental impact of the animal industry.
Estimates vary, but livestock are believed to account for up to 14 percent of all greenhouse gas emissions from human activities. In addition to carbon dioxide, agriculture produces two other gases in large quantities: nitrous oxide when fertilizers and waste are added to soil and methane. The latter are to a large extent burped by ruminants – mainly sheep and cattle – and account for more than a third of total agricultural emissions. An average ruminant produces 250-500 liters of methane per day. Globally, livestock are responsible for 3.1 gigatons of carbon dioxide emitted into the atmosphere annually.
But AgResearch scientists hope that it may be possible to reduce the contribution of animal production to global warming.
Their approach is based on the work of Shined Leahy, an AgResearch microbiologist who is currently assigned to the New Zealand Agricultural Research Centre. Methane produced by ruminants comes from about 3% of the huge number of germs that live in the scar, the first part of the intestine. The culprits belong to an ancient group called Archaeology, and they are able to live in an environment where there is no oxygen.
Through intestinal fermentation, these microbes decompose and ferment plant materials eaten by animals, forming methane as a by-product. In order to relieve the pressure that may build up in the production of this gas, the animals then burp it off.
However, to sift out the bacteria responsible for this, Leahy and her colleagues had to find a way to reproduce the oxygen-free state of the scar in their laboratory. Then, using DNA technology, they were able to sequester the genomes of some key species.
Understanding what distinguishes these microbes from other types, which are also important for digestion, is very important,” explains Leahy. – Through our research, we were able to study different types of gene sequences [in microbes] and select targets [common] for all methanogen species. They then became the main targets in the development of the vaccine.
This work allowed the AgResearch team to systematically develop vaccines targeting multiple microbial species simultaneously.
So far, despite numerous experiments, there is still no conclusive evidence that the vaccine reduces the amount of methane released by cows. Some Australian scientists made a similar attempt in the 1990s, but to no avail. The AgResearch team is confident that their genetics-based approach will yield better results.
But vaccination is not the only way to clear cows’ breath. Animals vary in methane production, and at least some of these changes are due to genetic differences. Eileen Wall, head of research at Country College Scotland, explains that it allows selective breeding of animals that produce less methane. She sees this as part of a broader breeding program aimed at producing healthier and more efficient sheep and cows – both of which also reduce greenhouse gas emissions per unit of meat and milk.
But breeding animals in this way can be time-consuming and expensive, warns Liam Sinclair, who studies scar metabolism at Harper Adams University in Shropshire, UK.
Another alternative is to feed the animals with food, which leads to less methane formation. This can be effective, but only partially, and if the diet allows animals to continue producing milk and meat, explains Phil Garnsworthy, who specializes in feeding dairy cows at the University of Nottingham.
“You can probably reduce your methane content by about 20-25% by changing your diet,” he says. One study by scientists at the University of California at Davis showed that global methane emissions from cows can be reduced by 15% by changing their diet. But Garnsuorsi believes more is possible. Often, farmers mostly use silage from herbs.
“If you move only to silage based on corn, you will see a 10% drop in methane production.
The more fiber a cow eats, the more methane it produces, but adding legumes and various oils such as flax and soybean to their diet can be useful, adds Sinclair.
“Better feeding makes animals more productive, and more productive animals produce less methane,” he says.
It’s also been shown that adding seaweed to a cow’s diet helps get rid of the insects that produce methane.
Masks and backpacks to collect gas
Some researchers have already suggested a new, weird approach – to put on cows backpacks to collect burps. Meanwhile, students at the Royal College of Art in London developed a device that could be attached to the nose of a cow to convert exhaled methane into less powerful carbon dioxide.
However, a more realistic alternative is still feed additives. For example, ionophores, which are already used in some parts of the world to increase the weight of animals, and can also be used to suppress methane-producing arches. But there are also some problems.
Ionophores, which are classified as antibiotics, are banned for use in animals in the European Union because of concerns about how excessive use of these agents in agriculture could increase the resistance of bacteria to medicines. The ban is controversial because ionophores are not used in medicine and act differently than therapeutic antibiotics.
Other supplements are available that can also help suppress methane emissions from livestock. Recently, 3-nitroxypropanol (3-NOP) has been of interest; it reduces the effectiveness of the chemical pathway by which archaeologists turn carbon into methane. The company that created the additive hopes for a 30 percent reduction in methane emissions.
Another option is to give cows probiotics or useful bacteria to improve their digestion. Elizabeth Latham, a former research fellow at A&M University of Texas and co-founder of Bezoar Laboratories, is developing a probiotic to combat methane from cattle and claims it can reduce emissions by 50 percent.
But these chemical inhibitors and probiotics will need to be added daily to the feed, and they will be difficult to deliver to animals that mainly feed on grass. Most likely, this will be an expensive solution to the problem. The vaccine will potentially only need to be injected once, or it may only need to be re-vaccinated annually.
Regardless of the approach used, interference with the structure of microbial life in the intestines will change its ecology – perhaps with unforeseen consequences. The intestinal microbial structure is closely linked to health, and its change may increase the risk of disease in cows. People even have some connection between intestinal bacteria and mood, although it is not clear if reducing the number of methane producing bacteria will depress cows and sheep and what effect this may have on their meat and milk.
Vaccine developers believe this is unlikely. But until further testing proves that interference with livestock microbes can reduce their emissions without harming the animals or products for which they are grown, the world will have to wait.
What will happen in the end?
Gene editing can make food more environmentally friendly, but whether it will be available to the public is another question. Despite the general scientific consensus that genetically modified foods are safe to eat, public resistance to GMOs has peaked in recent years.
Most of the achievements that the authors of this report suggest do not yet exist, and it will take years before they do. To achieve this, the report recommends that authorities reduce regulatory barriers to genetically modified plants and animals, increase investment in research and development in gene editing technologies and encourage researchers and companies to develop genetically editable climate solutions.
Meanwhile, scientists and companies developing genetically modified crops and livestock will need to convince the skeptical public that these products are safe and healthy and will not have negative consequences for the environment. While we should not rely on genetically modified plants and animals to solve the climate crisis, they may ultimately play a role in containing global emissions. As the climate crisis intensifies, buyers may have to be open-minded when genetically edited products finally appear on the shelves of grocery stores.