Why getting plants ‘drunk’ may be really good for them

By Mark Waghorn via SWNS

Getting plants 'drunk' insulates them against drought, according to new research.

They thrived when soil was soaked in alcohol - even after two weeks without water, scientists say.

The colorless liquid has the opposite effect on humans - making us woozy after a few beers, wines or whiskies.

It could be the answer to crops withstanding global warming.

Climate change may be affecting the production of corn and wheat by 2030.

Lead author Dr. Motoaki Seki, of the RIKEN Center for Sustainable Resource Science in Japan, said: "We find treating common crops such as wheat and rice with exogenous ethanol can increase production during drought.

"As in Arabidopsis, this is likely via changes in the metabolomic and transcriptomic profiles that regulate the drought-stress response.

"This offers us a cheap and easy way to increase crop yield even when water is limited, without the need for genetic modification."

Ethanol is neat alcohol. A small amount of the chemical is the same as a large number of normal alcoholic beverages.

In people, immediate effects include nausea, vomiting and intoxication. In large quantities, it can cause almost immediate loss of consciousness - and even death.

But Seki and colleagues showed it has a remarkable capacity to revive stressed-out plants.

Wheat, rice and Arabidopsis, a model plant for experiments, all flourished in soil with three percent ethanol.

They did not survive the fortnight of arid conditions when it was pre-treated with water, instead.

"Ethanol can help plants survive in times of drought. Adding ethanol to soil allows plants, including rice and wheat, to thrive after two weeks without any water," Seki said.

"As ethanol is safe, cheap, and widely available, this finding offers a practical way to increase food production all over the world when water is scarce, without the need for costly, time-consuming, and sometimes controversial production of genetically modified plants."

The global population will rise to almost 10 billion by 2050 - and 11 billion at the end of the century.

Along with global warming fueled increases in water shortages, famines will become regular unless action is taken.

One option is to find a way to prevent plants from dying when they don't have access to water.

Genetically modifying plants so that their stomata—the pores in their leaves—stay closed, has been somewhat effective because it prevents water from leaving the plants.

But making them is expensive and time-consuming. Countries with the greatest need might not have equal access to these modified crops.

Plants produce ethanol when deprived of water. The team reasoned it would protect them from future drought.

So they grew plants for about two weeks with ample water. Then, they pretreated soil with ethanol for three days, followed by water deprivation for two weeks.

About 75 percent of ethanol-treated wheat and rice plants survived after rewatering, while less than five percent of the untreated plants survived.

Having shown that ethanol can protect these two important crops from drought, they next set out to explain why by focusing on the model plant Arabidopsis.

First, they looked at the leaves. They found soon after ethanol-treated Arabidopsis plants were deprived of water, their stomata closed and leaf temperature went up.

By 11 and 12 days of water deprivation, these plants retained more water in their leaves than the untreated plants.

Then, the researchers analyzed gene expression before and during water deprivation and radio-tagged the ethanol before pretreatment.

This allowed them to see what processes were activated during drought and what happened to the ethanol after it was taken up by the plant roots.

Even before water was deprived, the ethanol-treated plants began to express genes that are normally expressed during water deprivation.

Additionally, around the same time that water content was dropping in untreated leaves, the ethanol-treated plants were making sugars from the ethanol and doing photosynthesis.

Treating the soil with ethanol mitigates drought on several fronts, Seki explained.

He said: "First, drought-related genes are expressed even before water is missing, giving the plants a head start in preparation.

"Then, the stomata close, allowing leaves to retain more water. At the same time, some of the ethanol is used to make a variety of sugars, which provide much-needed energy that is normally difficult to get with closed stomata."

The findings were published in Plant and Cell Physiology.