University of Sheffield scientists develop climate-resilient beans that reduce water usage

Scientists from the University of Sheffield’s Institute for Sustainable Food have engineered beans that could use up to 40 per cent less water, taking a huge step forward in the hunt to find ways to help agriculture to thrive in a rapidly changing climate.

Beans provide high-quality nutrition across Latin America, but the climate crisis is causing drought and heat waves in the region. As a result, scientists around the world are in a race against time to create stronger, climate-resilient bean crops to support food security in the area; especially as legumes are an important staple food group in the region.

The Pod Yield Project examined the differences between the common bean and the tepary bean, a variety which has been naturally grown in Mesoamerica and Mexico for thousands of years. With its ability to be grown in semi-desert environments the team observed how the tepary bean is better suited to its environment, including its less dense stomata, the microscopic valves on its leaves which are used to control water loss and carbon dioxide intake for photosynthesis.

By manipulating the size and density of stomata, researchers at the Institute for Sustainable Food were able to engineer bean crops that can conserve more water and maintain growth under drought conditions for longer than other types of bean; making them ideal for cultivation in hotter climates.

Professor Julie Gray from the University of Sheffield’s Institute for Sustainable Food, said: "Modern agriculture uses a lot of water - about 70 per cent of the global freshwater - but this resource is diminishing under climate change, and we desperately need to find new ways to allow farmers to reduce irrigation and still provide enough food for our growing population. We hope that our work will produce crops that use less water and are better suited to future warmer and drier climates."

In Latin America, up to 80 per cent of bean yields can be lost with the earlier onset of seasonal droughts. Due to this, it is also estimated that in Mexico alone novel bean varieties could save up to 3 per cent of the country's entire agricultural water use, the equivalent of 4.5 billion litres of water a year by using more drought resistance crops.

Loss of bean yields can also lead to serious economic problems due to the need to then import stocks from other countries. It is hoped that these newly developed beans will combat these issues.

Professor Gray said: “We have learned so much about the importance of bean crops from our Mexican partners and are delighted that we can apply our knowledge of stomatal biology to real world problems.”

“Moving forward, for the next phase of the study we are planning to do further glasshouse work and field trials of the soybean variety this year, working together with the Royal Botanical Gardens at Kew and in collaboration with partners in the US.”

Dr Caspar Chater, a research leader in natural capital and plant health at the Royal Botanical Gardens, worked on the project at Sheffield before taking up his position at Kew. He said: “It is critical we develop climate resilient beans by harnessing natural variation in drought resistance. We need new bean crops that farmers will be excited to grow and consumers will be happy to eat.”

The findings are especially important given the popularity of the legume food group in Latin America. In 2015, Mexico consumed an average of 8.6kg of beans per person, in comparison, people in the UK consumed less than 0.3kg of beans in the same year.

Additional information:

The research was carried out in partnership with the Institute of Biotechnology, National Autonomous University of Mexico and was supported by the Marie Skłodowska-Curie programme.