Game changer: New chemical keeps plants plump
A team led by UC Riverside has created a chemical to help plants retain water, which could stem the tide of massive annual crop losses due to drought and help farmers produce food despite climate change.
"Drought is the leading cause, closely linked to floods, of annual crop failure worldwide," said Sean Cutler, professor of plant cell biology at UC Riverside, who led the research. "This chemical is a new tool that could help farmers better manage crops when water levels are low."
Details of the team's work on this new, more effective water loss control chemical are described in an article published today in Science. This chemical, Opabactin, is also known as "OP", which is the slang of the player for "controlled", referring to the best character or weapon in a game.
"The name is also a cry to my 10-year-old son at home," says Cutler.
An earlier version of the OP developed by Cutler's team in 2013, called Quinabactin, was the first of its kind. It mimics abscisic acid, or ABA, the natural hormone produced by plants in response to drought stress. ABA slows down the growth of a plant, so that it does not consume more water than is available and does not wither.
"Scientists have long known that spraying ABA on plants can improve their drought tolerance," Cutler said. "However, it is too unstable and too expensive to be useful to most farmers."
Quinabactin appeared to be a viable alternative to the natural hormone ABA, and companies have used it as the basis for many additional research, filing more than a dozen patents based on it. However, quinabactin has not worked well for some important crops, such as wheat, the most widely grown staple crop in the world.
When ABA binds to a hormone receptor molecule in a plant cell, it forms two tight bonds, like hands that cling to handles. Quinabactin only attaches to one of these handles.
Along with other collaborators from the UCR and the Medical College of Wisconsin, Cutler looked for millions of different molecules that mimicked the hormones that would cling to the two handles. This research, combined with some chemical engineering, led to the OP.
OP grabs both handles and is 10 times stronger than ABA, making it a "super hormone". And it works fast. Within a few hours, Cutler's team saw a measurable improvement in the amount of aquatic plants released.
Given the rapidity of OP action, producers could benefit from greater flexibility in how they deal with drought.
"One thing we can do that plants can't do is predict the near future with reasonable accuracy," Cutler said. "In two weeks, if we think there is a reasonable risk of drought, we have enough time to make decisions - such as the application of the OP - that can improve crop yields."
Initial funding for this project was provided by Syngenta, an agrochemical company, and the National Science Foundation.
Cutler's team is now trying to "nerve" their discovery.
"That's what players say when the power of a weapon is reduced," says Cutler.
While OP slows growth, the team now wants to find a molecule that will accelerate it. Such a molecule could be useful in controlled environments and indoor greenhouses where precipitation is not as important a factor.
"There are times when we want to accelerate growth and other times when we want to slow it down," Cutler said. "Our research focuses on the management of these two needs."
