Genetic engineering techniques could play an important role in ensuring the future of global food security.
Many countries worldwide are facing the double burden of hunger and under-nutrition alongside overweight and obesity, with one in three people across the globe currently suffering from some form of malnutrition. In fact, it’s not unusual to find people with different forms of malnutrition living side-by-side.
While globally there are now more people who are overweight or obese than underweight, according to Global Food Security, around 795 million people face hunger on a daily basis while more than two billion people lack vital micronutrients (e.g. iron, zinc, vitamin A), affecting their health and life expectancy. Furthermore, nearly a quarter of all children aged under five are stunted, with diminished physical and mental capacities, and less than a third of all young infants in 60 low- and middle-income countries meet the minimum dietary diversity standards needed for growth.
Indeed, food security is still a growing problem. But new plant-breeding techniques could increase and accelerate the development of new traits in crops and help to increase production and yields. Genome-editing (GE) techniques in particular, notably a method called Clustered Regularly Interspaced Short Palindromic Repeats (Crispr-Cas), could in fact help to make agriculture more productive and environmentally friendly.
Up until now technologies such as chemical fertilisers, pesticides, herbicides, modern agricultural machinery and artificial selection have been used to increase production. Newer technologies, however, take an approach of altering the plant itself rather than spraying something onto it. The initial iteration of this was with genetic modification. This is where genetic engineering is used to add something and thus change its genetic structure.
Genetic modification (GM) techniques upped the ante by making available a much larger pool of genetic variation. This meant that the plants treated with genetic modification could have desirable characteristics such as drought-resistance.
Rene Custer, regulatory and responsible research manager at Vlaams Instituut voor Biotechnologie, a biotech institute based in Belgium, argues: “Conventional techniques such as genetic modification are less reliable and also mean lengthy wait times because the techniques are simpler: namely combining different varieties to see what you end up with. It has always been blind and random.”
Now newer plant-breeding techniques are coming to the fore that are seen as more reliable. These could be the means to further increase and accelerate the development of new, more desirable traits in plant breeding. GE techniques could help to make agriculture both more productive and more environmentally friendly – both of which tie into the need to end food poverty as well as reduce the environmental impact of agriculture (see box).
“Plant breeding and other agricultural technologies have contributed considerably to hunger reduction during the last few decades,” says Matin Qaim from the University of Göttingen, Germany. In his 2019 paper ‘Food Security: Impact of Climate Change and Technology’, he cites several authors in saying that GE could “contribute to higher crop yields, lower use of chemical fertilisers and pesticides, better crop resilience to climate stress, reduced post-harvest losses, and more nutritious foods”.
Nigel Halford, a crop scientist at the UK’s Rothamsted Research, one of the oldest agricultural research institutions in the world, looks at the difference between GE and GM. “With GM an extra gene is added – there is a modification. But with GE, although there might be a modification within the process, the end product is not genetically changed, rather modified to introduce or take out a property.
“The idea behind editing is to knock something out that you don’t want or introduce something that you do. It’s about mutation rather than introducing something new entirely,” he says.
He cites the example of rapeseed, which can be made to be more tolerant to herbicides if it has an enzyme added to it to make sure it cannot react to herbicides. This technique of neutering the plant’s ability to react to something can also be applied to taking out allergens and other negative factors.
“Although you could also do this using GM techniques the end result would not be 100 per cent reliable – more of a reduction rather than a removal or addition of something. With modification the end result is better because the original structure of the plant has not been added to, just modified,” he explains.
Adaptive symbiotic technology
Adaptive symbiotic technology is another development that could go far to help solve food poverty. Essentially this technology creates non-toxic and non-pathogenic microbes within certain types of symbiotic fungi, known as endophytes. They can grow alongside other plants and help them be more nutrient-efficient and tolerate environmental stress such as drought, salinity and temperature. This is a technique that can be applied to a wide variety of cereals, pulses, vegetables and industrial crops. In simple terms this is basically harnessing what is there already by using symbiotic, or natural, interactions between plants and microorganisms.
“Symbiotic technology uses fungi that interact with plants to change the nutrients, increase the plant yield and the overall quality of the crop,” says Nigel Halford, crop scientist at Rothamsted Research. “The farmer can buy these microbes to add to the crop themselves.”
One firm actively involved in this is US-based Adaptive Symbiotic Technologies (AST). It has collaborated with seed companies and growers in Australia, the Netherlands, Kenya, Argentina and India to trial and test its product line on various crops. The best results have come from India, where AST has used the technology under high-stress conditions and come out with good results. The crops tested include wheat, millet, okra, cotton, maize and rice. The trials were supported by grants from the US-India Science and Technology Endowment Fund and The United States Agency for International Development.
If successfully adopted by the agricultural industry, this technology would not only reduce food poverty by contributing to the future success of crops but also reduce reliance on chemicals. And while the technology can be used alongside chemicals, it has been found to be more effective once the chemicals are removed. Trials in temperate climates, for example, showed output rose by between 3 and 20 per cent. Thus potentially this technology gives a means to create more robust crops in a more environmentally friendly way by removing the chemicals.
Although there are many GE techniques, one has emerged that looks likely to take centre stage. Developed in 2012, the Crispr-Cas system is both relatively easy to use as well as being effective, experts have said.
“Crispr-Cas is a technique that has very wide acceptance within plant research and breeding companies. Although there are a few type of gene editing, Crispr-Cas is the one that seems to work best and most efficiently,” Custer notes. “Plant breeders basically want to improve their varieties to be more robust, to have resistances, to take out things that are not wanted and introduce things that are. So it makes sense for them to use the easiest and most efficient technique. For the most part this is Crispr-Cas.”
Crispr-Cas is already in use, with around 60 plant species having been altered to provide resistance to disease and drought and other environmental conditions. It has also been used to create crops with certain traits such as high-fibre wheat, or taking out allergens such as gluten. There has also been the introduction of new desirable traits such as in hard-to-breed crops like bananas.
Qaim cites “manifold” examples of gene-edited crops at or near the end of the research pipeline. They include fungus-resistant wheat, rice, banana, and cacao; drought-tolerant rice, maize, and soybean; bacterial-resistant rice and banana; salt-tolerant rice; and virus-resistant cassava and bananas.
Meanwhile, a paper by Janina Metje-Sprink and other researchers named ‘Genome-edited plants in the field’, cited the use of Crispr-Cas in the genome of at least 40 different plants, including niche crops such as gooseberry and watermelon. The paper said that the largest field trials with GE plants exist for rice and took place in China, where the size of the rice grains was increased. Meanwhile, trials with maize resulted in higher crop yield. Tomatoes too have been trialled and been proven to self-prune and made larger or smaller.
Clearly examples abound of where this has been beneficial but what, if any, are the risks? Firstly there are risks related to the process itself and secondly there are risks in relation to the end product with new traits.
Qaim says that 30 years of risk research related to GM crops suggests there are no new risks related to the breeding process and that GMs are not inherently more risky than conventionally bred crop varieties. But for gene-editing technologies such as Crispr-Cas a long safety record is not yet available, he says, because these technologies have only been used for a few years.
However, he says, because the point mutations developed so far are genetically indistinguishable from natural mutations, the expectation is that new types of risk related to the process of modification are unlikely.
The second types of risk, namely those related to a particular new trait, he says, are different. “Each new trait can have different effects. Herbicide tolerance, for instance, will differ in its environmental and health impact from traits such as drought tolerance or increased vitamin levels. Trait-specific risks can only be assessed case by case.”
As a result of this, Qaim believes that regulation by trait rather than process would make more sense. Indeed many countries, including the USA and Australia, have decided to regulate GE crops in the same way as conventionally bred crops.
In the European Union, however, the EU Court of Justice decided in 2018 that GE crops are automatically considered GMs, meaning that the same strict rules and regulatory procedures apply as for GM crops.
The UK’s response remains to be seen. In July 2019, Prime Minister Boris Johnson pledged to free the UK of the EU GM regime post-Brexit. “Let’s liberate the UK’s extraordinary bioscience sector from anti-genetic modification rules. Let’s develop the blight-resistant crops that will feed the world,” he said at the time.
Halford comments: “In the US, there is no regulation for GE. In Europe both GM and GE fall into the same bucket defined as ‘a change to DNA that could not occur naturally’. Thus it is easier to import GM and GE into Europe than it is to cultivate them. But they are already being used; maize, soybeans and rapeseed oils are all used routinely for animal feed.”
Differing regulation is likely to have an impact on where GE foods are taken up and where they are not. The lack of regulation in the US could pose a problem in that one GE food could be mixed with another and not recorded.
“One of the worries is that if GE is not regulated in the US then you might end up with something where the initial GE has been mixed with something else but that something else has not been registered or recorded and so although you can test what you have ended up with there is no means to know how you got there,” Halford says.
In Europe, meanwhile, further development could be hindered by the failure to recognise the difference between GM and GE food.
An interesting trend to note is that areas where food poverty is prevalent have been more open to GM conceptually. Argentina and Brazil, in particular, are significant producers of GM crops and GM is also grown in Asia. In Africa things have been slower to develop but Sudan, Egypt and Kenya have all made a start. “It’s fairly safe to say that where GM exists then GE will follow,” Halford comments.
Another possibility of note is that although GM has been largely adopted by multinationals, GE is relatively easy to do and thus there are a number of SMEs involved. The implication is that practical case-by-case uses to alleviate food poverty could come to the fore more quickly than with a large multinational where scale is key.
To do this the technology has to be combined with local contexts so that they are used depending on location, farm sizes, farmer literacy, access to information and government policies and their enforcement.
Qaim says: “It is important to understand whether crops developed with GE can be used successfully by smallholder farmers.” He looks to GM foods to see how that might play out with GE foods and says that farmers in developing countries could benefit more from GE than farmers in developed countries, who are already benefitting from GM.
“The reasons are twofold,” he explains. “First, farmers operating in tropical and subtropical climates often suffer from higher pest damage than can be reduced through GM adoption. Hence, effective yield gains tend to be higher than for farmers operating in temperate zones. Second, most GM foods are not patented in developing countries, so that seed prices are lower than in industrialised countries, where patent protection is much more common.”
The inference is that lack of demand from industrialised countries due to them already being involved in GM could make GE producers turn towards developing countries where the technology is more in demand and would also have more of an impact.
However, there is also the need to consider the use of GE in tandem with effective harvest and post-harvest practices to minimise food loss. Effective storage and conservation practices, for example, play a part in increasing the value of a harvest and identifying high-value-added products. The combination of factors work together to improve economic gains for processors and ensure long shelf-life and enhanced marketing of available foodstuffs at competitive prices.
“GE and in particular Crispr-Cas answers some of the problems around climate change and food security,” says Custer. “The actual crop management clearly comes into it as well. GE crops are but a piece of a complex jigsaw.”
Qaim concludes: “Of course, sustainable food and nutrition security requires more than GE crops alone. But against the background of further population growth, climate change, and a dwindling natural resource base it would be irresponsible to not harness the potential that modern plant biotechnology offers.”
Impact of climate change
Food security is a long-term issue. In the midst of the Covid-19 pandemic, the UN Foundation, leading food producers such as Unilever, Nestlé and PepsiCo, and others such as farmers’ organisations, academics, and civil society groups have written to leaders of the G7 and the G20, and to other countries to urge them to invest in food production and distribution. They say that environmentally sustainable food production and protecting farmers in the developed and developing world is key.
The letter also emphasised the need to invest in making the food system more environmentally and socially sustainable. In practice this would mean new investment to include the means to keep crop production levels high enough and to focus on making the crops themselves as nutritious as possible.
This is not a new issue. The 2015 United Nations Sustainable Development Goals aim to end global hunger by 2030. Although the previous 15 years had seen malnutrition levels halve due to international efforts and investment in agricultural and economic infrastructure, we still have significant levels of food insecurity in 2020 and that is likely to be made worse by Covid-19.
Add to that the impact of climate change where extremes of weather can have a significant impact on crop production at a time when the global population is increasing and the outcome is a struggle to get enough food to the people who need it. Many predict that countries will fight over food and water.
Agriculture is, of course, itself a contributor to global warming. In its 2019 report, ‘Climate Change and Land’, the IPCC said that agriculture accounts for about 25 per cent of global greenhouse gas emissions.
In a paper, ‘Role of new plant breeding technologies for food security and sustainable agricultural development’, Matin Qaim argues: “The increasing intensity of agricultural production has its problems. Climate change will likely affect agricultural production negatively through increasing mean temperatures, heat and water stress, and rising frequencies of weather extremes.”
Qaim adds: “Poor people in Africa and Asia will be hit hardest by climate calamities, not only because they are particularly vulnerable to price and income shocks, but also because many of them depend on agriculture for their livelihoods.”
Source: E&T Engineering & Technology
By Alison Ebbage