Plants Tricked Into Tolerating Drought

In a new breakthrough study, scientists have successfully tricked plants into tolerating drought and given vegetation across the globe hope of survival amidst the world's ever-changing climate.

Crops and other plants are constantly up against hostile environmental conditions, such as warming temperatures (2014 was the warmest year on record) and a lack of fresh water. But drought is among the top plant stressors, affecting their growth and development.

What's more, with extreme weather patterns becoming the new norm, according to the World Bank, drought conditions are expected to become more frequent or even worsen in some parts of the world. California is already experiencing the worst drought in a millennium, and the Southwestern United States will likely see megadroughts that last 30 years or more down the line.

Right now plants are ill-prepared for dealing with droughts - more so than scientists thought - but new research may just be their savior.

A team of researchers led by Sean Cutler at the University of California, Riverside has reprogrammed certain plant receptors to respond to the agrochemical mandipropamid, effectively helping the plants survive drought conditions.

"We successfully repurposed an agrochemical for a new application by genetically engineering a plant receptor - something that has not been done before," Cutler said in a statement. "We anticipate that this strategy of reprogramming plant responses using synthetic biology will allow other agrochemicals to control other useful traits - such as disease resistance or growth rates, for example."

Normally when vegetation is faced with drought, it naturally produces abscisic acid (ABA), a stress hormone that inhibits plant growth and reduces water consumption. Specifically, these arid, waterless conditions cause ABA to turn on a receptor in plants that closes stomata (guard cells) on leaves to reduce water loss. Unfortunately, ABA is costly to make, rapidly inactivated inside plant cells and light-sensitive, so practical use on crops has thus far been unsuccessful.

But now Cutler and his colleagues have come up with a way to trick plants into thinking they're being treated with ABA. Using synthetic biological methods, they developed a new version of ABA receptors in Arabidopsis and tomato plants, engineered to be activated by mandipropamid instead of ABA.

The researchers showed that when the reprogrammed plants were sprayed with mandipropamid, the plants effectively survived drought conditions (they withheld water for 12 days) by turning on the ABA pathway, which closed the stomata on their leaves to prevent water loss. In the absence of mandipropamid, these plants showed minimal difference from plants that did not possess the engineered receptor. (Scroll to reas on...)