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GM crops, quantity or quality…?

Image: International Rice Research Institute/Wikimedia Commons.
Golden Rice grain compared to white rice grain in screenhouse of Golden Rice plants.

Of all the contentious issues in plant biology at present, few are more divisive than genetically modified crops (‘plants used in agriculture, the DNA of which has been modified using genetic engineering techniques’). To date, the sort of engineering that has been carried out has largely been aimed at generating crops with resistance to damaging or disease-causing ‘pests’ such as insects (e.g. Bt cotton), or tolerance of herbicides so weeds that would otherwise compete with the crops can be chemically controlled. In both cases the noble aim has been to increase crop yields. And that is arguably needed to supply the food needs of an ever-increasing human population (which currently stands in excess of 7 300 000 000, or around about that number). That seems a laudable ambition, and its exploitation and more widespread application is applauded by scientists engaged in the development and use of such technology – and policy-influencers/makers who also agree that GM is ‘good’ (‘Staple crops, genetically modified for the purpose of improved pest control, have been widely cultivated for over twenty years and evidence suggests that they have delivered significant benefits, increasing crop yields while reducing the need for harmful pesticides’). And a major meta-analysis by Wilhelm Klümper and Matin Qaim concluded there was ‘robust evidence of GM crop benefits for farmers in developed and developing countries’. But we often have an ambivalence to the necessity of GM in Europe as many of us well remember the scandal of such phenomena as ‘grain mountains’ and ‘milk lakes’. Understandably believing that we have enough food, we may be forgiven for thinking that GM is not needed. But that view is more than a little insular and overlooks the needs of, and benefits that GM in Europe could bring to, the rest of the world, in particular places such as Africa whose citizens could benefit from application of the technology but may not be able to afford the GM seed.  But if we put considerations of food quantity aside (though we probably shouldn’t!), what about food quality? Poor food quality contributes to malnutrition, a most serious state of affairs, e.g. ‘When a person is not getting enough food or not getting the right sort of food, malnutrition is just around the corner. Even if people get enough to eat, they will become malnourished if the food they eat does not provide the proper amounts of micronutrients – vitamins and minerals – to meet daily nutritional requirements’. And malnutrition is a major, global issue, as highlighted by the Global Nutrition Report 2014, whose Executive Summary starts thus: ‘Good nutrition is the bedrock of human well-being, before birth and throughout infancy, good nutrition allows brain functioning to evolve without impairment and immune systems to develop more robustly’. Can GM offer any hope here? Yes, particularly in the field of biofortification [‘the practice of deliberately increasing the content of an essential micronutrient, i.e. vitamins and minerals (including trace elements) in a food, so as to improve the nutritional quality of the food supply and provide a public health benefit with minimal risk to health’]. That sounds good. Surely, this can’t be contentious? Well, one of the most high-profile biofortification projects concerns so-called Golden Rice. Here levels of β-carotene (a pro-vitamin A precursor) are enhanced in the rice grain in an attempt to ensure a dietary sufficiency of this essential organic compound, which is converted into vitamin A within the human body. And if you wonder whether vitamin A deficiency is a problem, consider that it causes not only blindness, but also a complex set of life-threatening illnesses, including reduced immune competence (with consequent mortality from increased severity of infectious diseases), night blindness, exacerbation of anemia through sub-optimal absorption and utilization of iron, and other conditions not yet fully identified or clarified… Vitamin A deficiency is prevalent in South America, Africa and south-east Asia, and is estimated to cause the deaths of more than 670 000 children under the age of 5 years, annually. Yet 15 years on from its creation (by Xudong Ye et al. – and with development of much-enhanced pro-vitamin A Golden Rice 2 in the interim), the world still awaits full commercialisation of Golden Rice, and exploitation of the health benefits it promises. Bemoaning the general reticence in adoption of this promising second-generation GM technology, Hans De Steur et al. present a carefully argued, detailed analysis of GM biofortified crop studies. Whilst they recognise that ‘transgenic biofortification is not a panacea for eliminating malnutrition… it does offer a cost effective intervention’. So, what’s the problem? What is the world waiting for?

[For more on biofortification, check out Philippa Borrill et al.’s Perspective Article, ‘Biofortification of wheat grain with iron and zinc: integrating novel genomic resources and knowledge from model crops’, and also ‘Iron nutrition, biomass production, and plant product quality’ by Jean-François Briat et al. – Ed.]

Written by Nigel Chaffey

Nigel is a botanist and was a full-time academic at Bath Spa University (Bath, near Bristol, UK) until 31st July, 2019. As News Editor for the Annals of Botany he contributed the monthly Plant Cuttings column to that august international botanical organ (until March 2019). He remains a botanist and is now a freelance plant science communicator who continues to share his Cuttingsesque items with a plant-curious audience. In that guise his main goal is to inform (hopefully, in an educational, and entertaining way...) about plants and plant-people interactions.

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