‘Overpowered’ super hormone offers hope for drought-proof crops

25 Oct 2019

Image: © Scott/Stock.adobe.com

Researchers have forged a new chemical that, when inserted into plants, can help them retain significant amounts of water in a drought.

Among the many negative consequences of the climate crisis, drought is one that is expected to become far more widespread in the decades ahead, leaving millions facing potential starvation.

However, in a bid to help stem the tide of massive annual crop loss, a team of researchers from the University of California announced the creation of a new chemical that could help plants hold on to more water during a drought.

This new chemical has been named Opabactin, or OP for short, with a nod to the gamer slang term for when an in-game weapon or item is ‘overpowered’.

“The name is also a shout-out to my 10-year-old at home,” said Sean Cutler, who led the study that has now been published to Science.

An earlier version of OP developed back in 2013 by Cutler’s team, called Quinabactin, mimics abscisic acid (ABA). This is a natural hormone produced in plants when they experience drought stress, resulting in slower plant growth to conserve water and prevent wilting.

Side-by-side comparison of plants with and without OP chemical.

An untreated plant versus one with OP on the right. Image: UCR

Rapid response

Despite the benefits of ABA being well known, farmers have refrained from spraying their crops with it because it is highly unstable and too expensive to use. Meanwhile, the initial promise seen in Quinabactin was lessened by the fact it doesn’t work well in staple crops such as wheat.

When ABA binds to a hormone receptor molecule in a plant cell, it forms two tight bonds, like hands grabbing onto handles. Quinabactin only grabs onto one of these handles.

Yet in OP, the team was able to create a chemical that can grab on to both and is 10 times stronger than ABA. Because the chemical can start working in a matter of hours, it could give growers more flexibility around how they deal with drought.

“One thing we can do that plants can’t is predict the near future with reasonable accuracy,” Cutler said. “Two weeks out, if we think there’s a reasonable chance of drought, we have enough time to make decisions – like applying OP – that can improve crop yields.”

While OP slows growth, the team now wants to find a molecule to do the opposite and accelerate growth, which could be useful in areas where rainfall isn’t an issue, such as greenhouses.

“There’s times when you want to speed up growth and times when you want to slow it down,” Cutler said. “Our research is all about managing both of those needs.”

Colm Gorey was a senior journalist with Silicon Republic