ALTHOUGH drought is the major threat in Australian cropping, flood and waterlogging is also a major player, especially in La Nina years like 2020-21 is likely to be.
So it has come as a boost to the industry that University of Oxford work, done partly in conjunction with the University of Sydney, has identified a particular enzyme within plants that can help it respond better to lower oxygen levels, such as found when the plant is waterlogged.
With the threat of climate change meaning more extreme weather events, including more intense downpours, the work has the potential to be important for Australian grain breeders in coming years.
Co-author of the study, Mark White, of the University of Sydney's school of chemistry, said he was confident the work would be taken up by plant breeders.
"We hope these findings can help produce flood-tolerant crops to help mitigate the devasting social and economic impact of extreme weather events on food production," Dr White said.
The work has been done investigating the natural response system of staple crops such as wheat, barley and rice to cope with temporary periods of waterlogging and identifying what is needed to trigger the response.
Many plants can survive temporary periods of flooding by activating energy pathways that do not rely on air in response to the low oxygen conditions in water.
The work identified that these responses are controlled by oxygen-sensing enzymes called the Plant Cysteine Oxidases (PCOs), which use oxygen to regulate the stability of proteins that control gene activity.
The research describes the molecular structures of the PCOs for the first time, identifying chemical features that are required for enzyme activity.
"The results provide a platform for future efforts to manipulate the enzyme function in an attempt to create flood-resistant crops that can mitigate the impact of extreme weather events," Dr White said.