How to achieve drought-resistant crops to ensure food securityCRAG researchers publish a review in Science about the ongoing biotechnological strategies to deal with drought, the greatest threat to agriculture
There is growing evidence that the frequency and intensity of drought are increasing as a consequence of global warming. According to the latest report by the Food and Agriculture Organization of the United Nations (FAO), in developing countries –the most populated–, drought alone causes more yield loss in crop fields than all pathogens combined, putting food security at risk. In an article published this week in the Science magazine, researchers from the Centre for Research in Agricultural Genomics (CRAG) discuss different biotechnological strategies to achieve drought-resistant crops, which could be used to mitigate the devastating effects of climate change on agricultural production. This work is part of the Science Drought Special Issue, which brings together international experts in this field.
How do plants protect themselves from water shortage?
As CRAG researchers explain in the article, plants use different mechanisms to prevent water loss and ensure their survival in conditions of water scarcity. These natural strategies include changes in the growth and architecture of the roots, the closing of the stomata –small openings in the leaves–, and the acceleration of the reproductive phase.
"The mechanisms plants use to protect themselves from moderate drought limit their growth, and significantly reduce crop yield", explains the senior author of the article Ana I. Caño-Delgado, CSIC researcher at CRAG.
The plant hormones abscisic acid (ABA), auxins and brassinosteroids play an essential role in the regulation of all these physiological responses of the plant facing water shortage.
The authors review the different experimental strategies that the scientific community has used to increase plant drought resistance by modifying signalling through the aforesaid plant hormones. One of these promising approaches is the one discovered by the group led by Caño-Delgado in 2018: the team demonstrated that by modifying brassinosteroid hormone signalling in the model plant Arabidopsis thaliana through a very specific receptor, BRL3, it was possible to obtain plants more resistant to drought without affecting their growth. These studies at Caño-Delgado laboratory are funded by a highly competitive Consolidator Grant from European Research Council (ERC).
A view to the future
As the world population continues to grow, reaching 10 billion people by 2050, it is expected that crop production will have to double to fulfil civilization’s basic needs, while fresh water will become increasingly scarce. Researching how plants respond to drought and designing new strategies to advance plant health are essential priorities for improving water use efficiency and guarantee future food security.
Currently, many research groups are conducting studies to meet this global challenge. "Some trials have already managed to improve drought resistance in Arabidopsis, tomato and wheat implementing very precise biotechnology tools, such as gene editing using CRISPR/Cas9 or the innovative optogenetics technique", says Caño-Delgado.
Along with the latest scientific-technical advances, all this knowledge on plant physiology, from roots to stomata, through phytohormones, opens new horizons to develop crops with greater resistance to drought without compromising yield. Bioengineering and the use of bio-stimulants –such as hormonal mimics– are the tools that will offer innovative strategies to fight water scarcity and address the needs of future agriculture.
Reference Article: Aditi Gupta, Andrés Rico-Medina, Ana I. Caño-Delgado. The physiology of plant responses to drought. Science. April 2020. DOI: 10.1126/science.aaz7614
About the funding: Ana I. Caño-Delgado’s research is funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 683163), by the Spanish Ministry of Economy and Competiveness and by European Regional Development Fund (ERDF). Andrés Rico-Medina is a predoctoral fellow from Fundación Tatiana Pérez de Guzmán el Bueno.