Activating natural "fire alarm" in plants could help crops beat drought
Plants can tell when they are facing the threat of a drought, thanks to an enzyme that not only senses drought conditions but also releases chemicals to help the plant get through dry patches. A new study from Australian National University identified the enzyme and hopes it will lead to the development of a chemical or method that can protect crops during droughts.
The researchers discovered the enzyme in plants like rice and wheat, which acts as a stress sensor to adverse light and water conditions, according to a study published in the journal Proceedings of the National Academy of Sciences.
The enzyme reacts to situations based on changes in the plant's chemical compounds such as hydrogen peroxide. The enzyme activates countermeasures by changing its shape.
"This sets off a 'fire alarm' in the plant, telling it to respond to drought by making beneficial chemical compounds, for instance," says Kai Xun Chan from ANU's Research School of Biology, who took part in the study.
Unfortunately, this reactive process doesn't always happen in time to ensure the plant's survival until the next rainfall. Plants like wheat are usually hit with droughts during the critical flowering and seed stages, and the enzyme may not react quick enough to release the chemical compounds the plant needs to make it through a drought.
This late-timed reaction can cause damage to the plants and affect crop yields that contribute to food supplies. NASA's Socioeconomic Data and Applications Center in New York City projects that the presence of climate change could cause drops in maize and rice yields by as much as 10 percent in some parts of the world by 2020.
However, the discovery of this enzyme could lead to the development of a new method or chemical that could activate the plant's natural defense mechanism before droughts start wiping out crops. Chan says his team hopes to find "potential compounds for a chemical spray" that can give crops an edge on droughts in further studies.
"We're really excited about the potential applications of this research, which range from genetic modifications and plant breeding to the development of a chemical spray that directly targets this sensor to set off the alarm in plants," Chan said. "This could save crops and ensure they produce bigger yields. The chemical spray would provide an innovative way to reduce the impact of drought stress."
Going forward, parts of the world are looking at more and more droughts as the Earth's climate continues to get warmer. NASA predicted in February of 2015 that the United States alone should expect to experience rolling waves of "megadroughts" in the last half of the 21st century, based on data collected from several climate models that stretched back to as far as 1,000 years. So a "drought-proofing" spray would certainly be a welcome advance.
Source: Australian National University