Pass The Vinegar, I Need To Water My Plants

After 14 days without water, only the plants treated with vinegar survived. NIKEN

Lack of water is becoming an increasing concern both for human and plant life throughout the world. Now comes the news that scientists in Japan have discovered that ‘watering’ plants with vinegar can help them survive longer under drought conditions. I don’t know about you, but I’m reaching for that bottle of white vinegar right now to see if my hydrangeas wouldn’t like a swig.

The Study

Last week, scientists at the RIKEN Center for Sustainable Resource Science (CSRS) published the results of a study that showed huge promise for thirsty plants of the future. Researchers revealed that they had stumbled upon a new biological pathway in certain species that sprang into action in times of water stress. By studying the pathway and the chain of chemical reactions within it, the scientists made a surprising discovery. They found they could induce greater drought tolerance in certain plants by growing them in vinegar.

Most of us are familiar with vinegar’s miraculous cleaning and anti-bacterial properties, but helping plants cope with drought? Now that is shocking news indeed.

My hydrangea showing signs of water stress 

A little plant named Arabidopsis

It all started with a collaborative effort to understand the plant Arabidopsis, also known as thale cress. A relative of cabbage and mustard, this genus of small flowering plants was the first species to have its entire genome sequenced. As a result, it is considered a model organism for studying plant biology.

Perhaps most interestingly, Arabidopsis is also known to exhibit strong drought tolerance. This is due to a mutation to an enzyme called HDA6. Specifically, the mutation allows the plant to grow normally without water for extended periods of time.

Microscopic view of anther of Arabidopsis, also known as thale cress

HDA6 acts as a switch

Indeed, initial testing showed that when experiencing drought stress, Arabidopsis uses HDA6 to activate a biological pathway that produces acetate, which is also the main component of vinegar. The HDA6 enzyme acts as a switch, controlling which type of metabolic pathway is active. While most plants are busy using metabolic pathways to break down sugar for energy, in times of drought, Arabidopsis switches to this acetate-producing pathway.

Clearly there was something going on. To find out how this switch works in times of water stress, scientists conducted an experiment. They grew normal plants under drought conditions, treating some with water, some with organic acids and others with acetic acid. After 14 days, they measured the results. Surprisingly, 70 percent of the plants treated with acetic acid were still living. Conversely, all of the other plants had died.

Microscopic view of stem epidermis of thale cress showing hairs and stomata

A link between acetate and drought performance

By measuring the amounts of acetate in the Arabidopsis, the team discovered that there was a direct correlation between the amount of acetate the plants produced and how well they performed under drought conditions. Even more exciting, the team carried out the same experiment on rice, wheat and maize and these species’ tolerance increased, too, when grown in optimal acetic acid concentrations.

Close-up of rice plant

It goes without saying that the implications of this research are huge. In an increasingly water-stressed future, this discovery might offer a simple, low-cost alternative to other strategies like genetic engineering. Still, I’m not sure if vinegar will help my hydrangeas survive another scorching Maryland summer, but it’s worth a try. I’ll let you know.