The future of eating: How genetically modified food will withstand climate change

Discover which foods can be genetically modified, how they can be improved and whether you need to worry about eating them.

What is genetically modified food?

Genetically modified (GM) crops are plants that have had their DNA changed by scientists to create desired traits. This is often done by adding just one gene from a close wild relative.

For example, crops can have their DNA altered to engineer plants that require less water to grow or are resistant diseases or pests. More ambitious projects are underway to engineer crops that make their own fertiliser. This type of technology could be key in making some of our most important crops more resilient in the face of climate change. It could also decrease the chemicals and energy needed to grow them. This could improve global food security.

Wheat

Wheat is the most commonly grown crop across the world by acreage. It’s often used to make bread, pasta and noodles. It’s also used to feed livestock.

Our researcher Professor Matt Clark, who studies wheat DNA, is helping to find ways to meet the demand for this vital crop.

It took more than 600 scientists working together to sequence the wheat genome in 2018. This was once thought to difficult to do, as the wheat genome is five times bigger than the human genome.

By understanding and changing wheat genomes, scientists like Matt are helping to protect the crop for future generations. Breeders will be able to select traits that’ll improve wheat harvests and help to secure food stores for billions of people around the world.

Wheat can be bred to withstand severe weather and disease, both of which could become more common as the world warms.

There are also wheat strains being engineered to produce flour with increased iron levels. Raising the nutritional quality of crops is known as biofortification. The ongoing trial, which is being carried out at the John Innes Centre in Norwich, has shown that the new grain contains double the amount of iron compared to a normal grain. This could help to reduce levels of iron deficiency-related anaemia globally. Anaemia is a condition where your blood is unable to carry oxygen efficiently due to low levels of red blood cells or haemoglobin. It’s especially common in girls and young women.

Maize

Maize – sometimes referred to as corn in the US and Canada – has seen demand surge globally because it’s used to feed animals and to create new fuels.

In 2019, researchers in the USA successfully increased corn yields by 10% by changing the gene that controls its growth. This modification has proved successful even in poor conditions – plants were given bigger leaves to improve how they turn sunlight into sugar and boost how efficient they are at using nitrogen in the soil.

Genetic modification can have unexpected positive effects, too. Corn damaged by insects contains fumonisins – toxins generated by fungi introduced to the corn by insects – which are thought to cause cancer. There’s a link between people who eat lots of corn, such as populations in South Africa, China and Italy, and higher rates of oesophageal cancer. So, corn that’s been engineered to require fewer pesticides may also be safer for humans and animals to eat.

Rice

Around 20% of calories consumed across the world come from rice, and it’s the main food source for three billion people.

But the places where rice is most often grown, including areas of India, Bangladesh and China, are constantly at risk of flooding. Rising sea levels and increasingly intense tropical storms mean that this problem is only going to worsen.

One solution is scuba rice, which has been bred to withstand being soaked in flood water. It’s been successfully grown in southeast Asia.

Genetic modification can also make rice kinder to nature. Rice paddy fields are a big source of the greenhouse gas methane. But the creation of the SUSIBA2 variety, which contains a gene from the barley plant, is helping. A three-year trial showed that this method increased yield by 10% while reducing methane emissions.

The C4 Rice Project, led by a team from 15 institutions across eight countries, is aiming to develop rice with a C4 photosynthetic pathway. This is essentially an advanced form of photosynthesis that has naturally evolved in other crops, such as maize. If it could be engineered into rice, it could make the crop more efficient in hot and dry conditions, possibly increasing yields by 50%.

The University of Sheffield is one of several institutions working on growing rice with fewer stomata – tiny openings used for gas exchange. This will result in less water being lost by the plant and better performance in exceptionally hot or wet conditions. Results so far show that lower stomatal density means that 60% less water is used. When 4,000 litres of water are needed to grow a kilogram of rice, and rice uses 70% of the agricultural water supply in China, this could be a significant saving.

Dr Haiyan Xiong is working on a similar strategy. Her PhD and postdoctoral work in China focussed on introducing the drought-resistant gene found in upland rice, which grows in dry and hilly conditions, into lowland rice. Lowland rice tends to be better quality but less hardy, so the aim is to merge the desirable traits of both crops.

Xiong’s team has identified three genes that could help make rice more resistant to drought. Her work at the University of Cambridge has been aimed at changing rice plants so they’re better at converting the energy from sunlight into food.

Xiong’s upbringing in rural Sichuan drew her to a career researching rice. She witnessed drought conditions first-hand, which led to a dream of “becoming a scientist who can contribute to improving rice resistance to drought stress”.

“Rice is not only one of the most important food crops in the world – it’s also a model plant for studying other cereal crops,” she explains.

Soy

Soya beans are the Americas’ most exported crop, making up 82% of its agricultural exports. Around 45% of this soya is crushed to produce oil and meals that are then exported globally.

Among these crops are genetically modified soybeans that have been spliced with a pigeonpea gene. This increases their resistance to a common crop disease called Asian soybean rust (ASR). ASR is caused by a fungus. It’s only treatable by introducing the fungi-resistant trait of other legumes to increase resistance and improve crop yields.

Are GM crops good or bad?

Some people are wary of genetically modified crops. This can often be due to concerns about the cost of seeds, issues surrounding herbicide resistance and worries about allergens and safety.

There are fears that crossing species could inadvertently introduce allergens, such as nuts, into the food chain. This appears unfounded, as to date no adverse reactions have been found in any approved GM products.

Others worry that modified plants could pollinate wild varieties and cause hybrids to pop up. For this to happen, the GM trait would need to be able to survive in the wild, which is not always possible, and GM crops can be designed to be sterile.

In fact, research has shown that there’s nothing that differentiates GM crops from naturally occurring ones in terms of health or safety. GM crops can be a force for good by offering an alternative to spraying pesticides that pollute groundwater and can kill surrounding crops.

Globally, GM crop uptake is divided. In some regions, billions of people have eaten GM crops for decades. In contrast, the European Union is generally resistant to the use of GM foods, though it does import GM animal feed.

Many European countries, including France, Germany and Croatia, have completely banned the cultivation of GM foods. Others, such as Spain, the Czech Republic and Portugal, grow GM crops. The USA is one of the widest growers and adopters of GM foods with 60% of processed foods containing ingredients from engineered soy, corn or canola.

The future of genetically modified crops

What does the future of GM crops hold? The Alliance for Science at Cornell University in the USA is currently working on corn that can resist insects and drought for use in Africa. If farmers plant corn that could do this organically, they could save money on fertiliser and pesticides.

Revolutionary gene-editing tools, such as CRISPR, can be used to precision-edit genetic material, even to the level of changing a single base of DNA. This has the potential for enormous worldwide benefits. For this reason, the 2020 Nobel Prize in Chemistry was awarded to the discoverers of CRISPR – Professor Emmanuelle Charpentier and Professor Jennifer Doudna.

There’s no magic fix to climate change and no sure-fire way to make agriculture more sustainable. But GM crops are helping farmers to adapt to the issues presented by our changing world. These crops can result in better yields, survive droughts and floods, and be more resistant to pests. These characteristics give us the ability to provide enough food for the increasing global population, while reducing the carbon footprint of agriculture.