Skip to menu Skip to content Skip to footer
News

Scientists tackle rusty plant threat

19 December 2022
Spray bottle on plants.
Treating myrtle rust.

University of Queensland scientists have developed an environmentally friendly RNA-based spray to help combat myrtle rust, which has wiped out many Australian plants.

Developed in collaboration with Department of Agriculture and Fisheries forest pathologists, the spray induces RNA interference (RNAi) – a natural way to shut down protein translation – which means it could slow the spread of myrtle rust through bushland, home gardens and nurseries.

PhD candidate Rebecca Degnan said in the decade myrtle rust had been in Australia it had become a huge problem, with more than 350  native hosts.

“Of those plants that have been screened, only three per cent were completely unable to be infected, and more than 40 species have been deemed conservation priorities because of damage from myrtle rust,” Ms Degnan said.

Molecular plant biologist Dr Anne Sawyer said the team wanted to find an alternative myrtle rust control to fungicides.

“Growers rely heavily on fungicides, but they come with a lot of problems such as being harmful to humans and beneficial organisms like bees and monarch butterflies as well as water contamination,” Dr Sawyer said.

Decorative
“Pests and pathogens can also develop resistance to chemicals and consumers are becoming more aware of residues on their fruit and vegetables.

“We already knew that RNA interference works against other plant pests and pathogens, and our research found rusts are very amenable to this method when we sprayed the double-stranded RNA onto the plants.”

Dr Sawyer said the early results were very positive, and further research would test the spray in more uncontrolled conditions outside of the lab and glasshouse.

“Now that we’ve seen the proof of concept of RNAi in myrtle rust, there are a lot of possibilities for other rusts as well,” Dr Sawyer said.

“It’s really exciting, especially when you talk to people who have been working on myrtle rust for a long time and have seen the damage it can do.”

The research is published in Molecular Plant Pathology.

Images are available via Dropbox.

Image above left: PhD candidate Rebecca Degnan, Dr Anne Sawyer and DAF's Dr Louise Shuey working on myrtle rust research.

Media: Dr Anne Sawyer, a.sawyer@uq.edu.au, +61 (0)422 285 190; Rebecca Degnan, r.degnan@uq.net.au, +61 (0)417 166 667; QAAFI Communications, Natalie MacGregor, n.macgregor@uq.edu.au, +61 (0)409 135 651.

Related articles

A blonde woman in jeans and sneakers sits on a rock in the bush smiling.

Transforming communities: 2026 UQ Alumni Award winners

A Totally Wild legend, a leading parenting expert and a pioneer in Queensland’s community sector are among The University of Queensland’s 2026 Alumni Award winners.
16 October 2026
Three researchers wearing blue protective lab gowns stand among rows of potted chickpea plants inside a controlled-environment plant research facility.

Turning up the heat on chickpea yield

A University of Queensland study has outlined a practical pathway for accelerating the development of heat adapted chickpeas using data from new ‘omic’ technologies. PhD candidate Callum Jamie said the suite of technologies offered tremendous opportunities to understand how a complex trait like heat tolerance works. “The narrow genetic diversity in the elite chickpea gene pool has limited conventional breeding’s effectiveness for stress tolerance,” Mr Jamie said. “These technologies have improved our capacity to dissect trait architecture and phenotype secondary traits but their use in chickpeas has been limited.” The technologies include genomics, epigenomics, transcriptomics, proteomics, metabolomics, phenomics and enviromics, and help provide a comprehensive picture of biological systems. Epigenomics helps understand what controls gene activity; transcriptomics considers gene expression; proteomics protein production; metabolomics looks at biochemical processes; phenomics observes traits; and enviromics considers environmental factors influencing outcomes. Mr Jamie said previous studies had focused on just 1 to 2 -omic datasets, a small number of genotypes, and single tissues. This has meant it was hard to infer what results meant for trait architecture and mechanisms and the ability to extrapolate the information to breeding populations was limited. There have also been challenges around cost, scalability and integrating very different types of data to make the technologies useful. To overcome the hurdles, Mr Jamie’s research at the Queensland Alliance for Agriculture and Food Innovation has resulted in a proposed staged approach. It would start with genomic prediction and phenotyping, before adding -omic layers as costs fall and unknowns were resolved. “These technologies are novel and we still don’t know which information provides added value and how best to integrate all of this data to achieve an outcome,” Mr Jamie said. His PhD is supported by the Grains Research and Development Corporation (GRDC) and the International Research Training Group (IRTG) Accelerating Crop Genetic Gain and is aligned to a project which aims to fast-track the development of chickpea varieties adapted to high temperatures. Project leader Dr Millicent Smith said heat stress causes severe yield implications through flower and pod loss, reduced pollen viability and impaired grain filling. “Late sown chickpea is particularly in the firing line across most of Australia's crop in southern Queensland and northern New South Wales,” Dr Smith said. “We want to ensure that Australian growers maintain their competitive edge. “New varieties with improved genetics to cope with heat stress are essential for the future. “This work, suggesting a staged approach to utilising the new -omic technologies, is an exciting frontier.” The research was published by Food and Energy Security. Callum Jamie’s PhD is supported by the Grains Research and Development Corporation (GRDC) and the International Research Training Group (IRTG) Accelerating Crop Genetic Gain.
15 October 2026

Media contact

Subscribe to UQ News

Get the latest from our newsroom.