WA researchers find new ways to breed resistant crops after ‘big’ scientific discovery

WA researchers have found new ways for breeding crop varieties resistant to diseases such as septoria nodorum blotch, after finding a key genetic mechanism behind the way pathogens infect crops. Centre for Crop and Disease Management, along with collaborators from the Curtin Health Innovation Research Institute and CSIRO, identified and validated the function of a specific DNA sequence linked to genes that cause wheat damage. The researchers studied the genetic mechanism in Parastagonospora nodorum, a fungus that causes septoria nodorum blotch of wheat, leading them to find the molecules responsible for damaging wheat. The findings were published in scientific journal PLOS Pathogens. CCDM director Professor Mark Gibberd said he was proud of the team for reaching a discovery that was “eight years in the making”. “By persisting through countless challenges, they have got to the bottom of the scientific mystery and have reached a conclusion that will help improve disease resistance not only in wheat but potentially against canola diseases too,” he said. “This research is an example of CCDM’s ability to work deeply and collaboratively on blue-sky research to ensure Australian agriculture is a global leader in research and innovation when it comes to grain production.” “A few years ago the team had discovered the transcription factor and knew that it regulated effectors but were unsure how it regulated them,” he said. Former CCDM PhD student Evan John said he hoped to transfer this knowledge to other diseases to improve the identification of necrotrophic effectors and other virulence-associated genes. “This discovery of the DNA consensus sequence is a big deal for disease resistance breeding research, as it means we now know how the pathogen’s effectors are activated to attack a plant,” Dr John said. “What’s exciting about this research, is that it can be used as a regulatory model, because the same Pf2 transcription factor is found in other fungal pathogens that cause diseases such as yellow spot of wheat, blackleg and black spot of canola. “Based on our current knowledge, it looks like Pf2 is operating by the same mechanism there.” Curtin University associate professor Kar-Chun Tan called the research a “big win” for growers in combatting diseases. “Now, knowing the genetic code of the DNA sequence targeted by Pf2, we can narrow down potential effector genes that are associated with the specific DNA consensus sequence, and prioritise these genes for effector discovery,” Associate Professor Kar-Chun Tan said.