Drought-proof crops under development

The Australian National University (ANU) has led an international research effort into how plants, such as rice and wheat, sense and respond to extreme drought stress. Published in the journal Proceedings of the National Academy of Sciences, their study could lead to the development of next-generation, drought-proof crops.

Lead researcher Dr Kai Xun Chan said the team discovered an enzyme that senses adverse drought and sunlight conditions. He explained, “The sensor in plant leaves is constantly sensing the state of its environment in terms of water and light levels.

“The sensor is able to sense when conditions become unfavourable, such as during extreme drought stress, by changing itself into a form with altered shape and activity.

“This sets off a ‘fire alarm’ in the plant, telling it to respond to drought by making beneficial chemical compounds, for instance. But in the field, this can occur too late and the plant would have suffered damage already.”

However, Dr Chan said, “If we can get the alarm to go off at the first signs of water deficit, we can help the plant survive severe droughts.”

By activating the sensor alarm faster during a dry season, the plant can activate countermeasures in its leaves to prevent unnecessary water loss and ensure that the plant survives until the next rainfall. More drought-tolerant crops would be crucial to helping ensure global food security, reducing the impact of drought on the national economy.

ANU researchers Dr Peter Mabbitt and Associate Professor Colin Jackson, using X-ray facilities at the Australian Synchrotron, enabled the team to create a 3D model of the sensor enzyme. Dr Chan said they will use this model and a computer program to identify candidate chemical compounds that match well with the enzyme’s structure.

“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,” Dr Chan said.

“Within two years, we hope to identify potential compounds for a chemical spray which will rescue crop yields. We would then need to perfect a compound in consultation with farmers and other industry players.

“We have already received funding from ANU Connect Ventures Discovery Translational Fund for this follow-up project.”