Scientists engineer wheat to survive droughts

Wheat is a staple food for millions of people – but as extreme droughts become more frequent, farmers face the prospect of dwindling yields
Wheat is a staple food for millions of people – but as extreme droughts become more frequent, farmers face the prospect of dwindling yields

Scientists have engineered wheat that uses water more efficiently while maintaining yields in the event of a drought.

Agriculture accounts for 80-90 per cent of freshwater use around the world, and on average it takes more than 1,800 litres of water to produce a single kilogram of wheat.

Yet as water supplies become scarce and more variable in the face of climate breakdown, farmers will need to produce more food than ever to feed a growing population.

Scientists at the University of Sheffield found that engineering wheat to have fewer microscopic pores - called stomata - helps the crop to use water more efficiently, while maintaining yields.

Like most plants, wheat uses stomata to regulate its intake of carbon dioxide for photosynthesis, as well as the release of water vapour.

When water is plentiful, stomatal opening helps plants to regulate temperature by evaporative cooling – similar to sweating.

In drought conditions, wheat plants normally close their stomata to slow down water loss – but wheat with fewer stomata has been found to conserve water even better, and can use that water to cool itself.

During the study, published in the Journal of Experimental Botany, the scientists grew wheat in conditions similar to those expected under climate breakdown – with higher levels of carbon dioxide and less water.

Compared to conventional wheat, the engineered plants used less water while maintaining photosynthesis and yield.

The research builds on work to develop climate-ready rice, which found that rice with fewer stomata used 40 per cent less water than conventional breeds and was able to survive drought and temperatures of 40C.

In a separate study, scientists also found that plants engineered to have fewer stomata are less susceptible to diseases.

They hope to be able to replicate these findings in crops such as wheat and rice.