Give plants ethanol to quench thirst

A growing world population and water scarcity as a result of global warming are putting pressure on food production. If we want to avoid shortages in the future, we need to make production more resilient in the face of drought.

One possible solution, which is already being implemented in some countries, is the production of genetically modified organisms (GMOs). But gene editing is expensive and time consuming. Thus, the areas where food production is under the greatest stress do not always have access to those adapted crops. There is an urgent need for a cheaper and more accessible alternative.

A team of biotechnologists at the Japanese research institution RIKEN, led by Seki Motoaki, may have an answer. Seki and his team found that pretreating the soil with ethanol better protects plants from drought stress. They were inspired by the plants themselves: They actually produce ethanol during drought stress.

For their experiment, the researchers watered plants with enough water for two weeks. Then they treated the soil with ethanol on some plants. Another part did not receive any ethanol treatment. Both groups were deprived of water for two weeks.

Wheat without (left) and with 3 percent ethanol in the soil. Tests on rice and a typical Arabidopsis plant yielded similar results. credit: RIKEN

closed stomata

What did you turn? 75 percent of the plants treated with ethanol survived dehydration. Less than 5 percent of the untreated plants survived. “Exposing common crops like rice and wheat to external ethanol increases crop yields during drought,” says Seki. External ethanol is added from the outside. The factory does not produce it itself.

The researchers also set out to find the reason for this modified drought tolerance. They found that pretreatment of soil with ethanol reduces drought stress in several ways. First, exposing plants to exogenous ethanol allows expression of drought-related genes. For example, plants that grow on treated soil are better prepared for drought.

Ethanol in the soil causes plants to close their stomata. Stomata are a type of pore in the leaf through which water can be lost. At the same time, the plant uses exogenous ethanol to produce sugars. This is usually difficult when the stomata are closed.

Future research should show how ethanol treatment affects soil life. After all, healthy soil consists of a diverse mix of soil life.

Source: RIKEN Center for Sustainable Raw Materials, Japan