New Chemical Boosts Drought Tolerance in Plants: Combating Climate Change

As our climate changes, plants face increasingly harsh conditions. Now, scientists have found a way to help plants cope with drought. They've discovered a synthetic chemical, quinabactin, that mimics a naturally produced stress hormone that improves water use and stress tolerance.

When a drought occurs, plants naturally produce abscisic acid (ABA), which turns on certain receptors in plants. While spraying ABA on plants can help them survive drought, though, the process is expensive and impractical for farmers. Quinabactin, in contrast, is far cheaper and could potentially be used to help create hardier plants.

Drought is starting to become a real problem in the United States and throughout the world. In fact, farmers witnessed record-breaking extremes in both temperature and drought in the U.S. over the past two summers. The result was a worldwide increase in food costs. These events, unfortunately, are likely to continue if climate change persists.

All land plants have water sensing and drought response systems that are set to maximize their fitness in the environments they live in. Yet over the years, farmers have chosen to cultivate fast-growing varieties of crops--and these crops don't always originate from drought-tolerant progenitors. As a result, some crops simply can't perform in years where there's drought.

In order to better understand how plants can survive drought conditions, researchers worked on Arabidopsis, a model plant commonly used in labs. More specifically, the scientists looked at one of the plant's endogenous systems involved in drought responses. During drought conditions, plants close their stomata, small pores in their leaves. ABA regulates this closure, regulating the loss of water through evaporation.

"If you can control the receptors the way ABA does, then you have a way to control water loss and drought tolerance," said Sean Cutler, one of the researchers, in a news release. "It has been known for many years that simply spraying ABA on plants improves their water use and stress tolerance, but ABA itself is much too expensive for practical use in the field by farmers."

After searching through thousands of molecules, the researchers eventually found a new molecule could mimic ABA: quinabactin. The new chemical could potentially be used to help plants survive drought conditions--a crucial adaptation if climate change worsens.

The findings are published in the journal Proceedings of the National Academy of Sciences.