A researcher at the University of Sydney has discovered and defined the sequence of an important gene behind leaf rust resistance in barley. The breakthrough by Dr Hoan Dinh could significantly progress the fight against rust disease, which decreases global food production significantly each year.
According to GRDC, rust in wheat and barley costs growers $350 million per year in productivity losses and fungicides. Researchers have been aware of the gene, known as Rph3, for more than 50 years and used the gene to protect barley crops against leaf rust in Australia until a new strain of the leaf rust pathogen emerged in 2009. However, greater knowledge of the gene and its mechanism to protect barley could help control the disease in the future.
“Plants and their pathogens generally co-evolve over time. It is similar to the way bacteria develop resistance to antibiotics. It’s like an arms race,” says Professor Robert Park, the director of cereal rust research at the University of Sydney’s Plant Breeding Institute and Dr Dinh’s PhD supervisor.
“In this case, even though the rust fungus had defeated the resistance gene, we wanted to understand how the gene worked, to see if it could be deployed with other genes – or even if its sequence could be altered to be made effective again.”
“Hoan undertook painstaking work over three years to isolate the gene from the barley genome, which is about the same size as the human genome. He found that the Rph3 gene is a new class of resistance gene in plants generally, which has led our research in a new direction that we think will advance rust resistance,” Professor Park says.
The use of resistance genes in crop species such as wheat and barley has long been considered the most cost-effective and environmentally friendly method of preventing rust outbreaks. Research indicatesthat genetic resistance saves Australian wheat and barley growers more than $1 billion every year.
This research has been published in the journal Nature Communications. It was supported by GRDC, the Gatsby Foundation and an Australian Awards Scholarship.
More information: International scholarship student leads barley rust breakthrough
Boosting wheat breeding
Researchers from the University of Adelaide and the UK’s John Innes Centre have identified a gene in wheat that improves yield and can increase protein content in the crop by up to 25 per cent. The discovery has significant implications for the nutritional and economic value of the crop.
“Little is known about the mechanism behind drivers of yields and protein content in wheat production,” says Dr Scott Boden, from the University of Adelaide’s School of Agriculture, Food and Wine, who led the research.
“Discovering a gene that controls these two factors has the potential to help generate new wheat varieties that produce higher-quality grain.
“As wheat accounts for nearly 20 per cent of protein consumed worldwide, the impact of this research can significantly benefit society by providing grains with a higher protein content, which could therefore help produce more nutritious food, such as bread and breakfast cereals.”
According to the University of Adelaide, this work is the first known example where screening of a mutant population has both identified a gene that controls reproductive development in wheat and, simultaneously, has the potential to help improve the nutritional and economic value of the crop.
“The increase in protein content occurs without the trade-off of a reduced yield, so this discovery has even better potential to provide economic benefit to breeders and growers than just the increased nutritional value by itself,” Dr Boden says.
The team expects that the new wheat varieties will be available to breeders in two or three years, which could then translate to benefits for growers in seven to 10 years.
The team’s findings were published in the journal Science Advances. This project was funded by the UK Royal Society, the UK Biotechnology and Biological Sciences Research Council, the Australian Research Council, the South Australian Grain Industry Trust and the University of Adelaide’s Waite Research Institute.
More information: Higher wheat yields and protein content on the horizon
The secret carbon decisions of plants
As Australia looks to lock in and meet reduced carbon targets, research at the University of Western Australia (UWA) has found that plants make their own ‘secret’ decisions about how much carbon to release back into the atmosphere via a previously unknown process.
The discovery has “profound implications” for the use of plants as carbon stores, according to Professor Harvey Millar from UWA’s School of Molecular Sciences and an author of the study published in Nature Plants.
Dr Millar says the findings mean plants of the future could be designed to meet the world’s food needs while also aiding the environment.
UWA researchers are now involved in long-term international partnerships to find better ways to use energy from respiration to redirect carbon to biomass without limiting a plant’s ability to grow and protect itself from pathogens or harsh environments.
More information: The secret carbon decisions plants are making about our future
GM wheat gaining momentum
Growers in Argentina are reportedly about to start planting genetically modified (GM) wheat for the 2022-23 season. The so-called HB4 GM wheat variety, developed by Bioceres, is more tolerant to water scarcity and resistant to the herbicide glufosinate-ammonium. According to Bioceres, HB4 drought-tolerance technology has been shown to increase wheat yields by an average of 20 per cent in water-limited conditions.
Australia’s food regulator, Food Standards Australia New Zealand, has already approved the sale of imported foods made from the GM wheat, with the application submitted by Trigall Genetics. Australia joined the US, Brazil and Colombia in approving the sale and use of food derived from HB4 wheat.
Widespread media coverage recently quoted Bioceres chief executive Federico Trucco as saying that the company plans to seek approval from the Office of the Gene Technology Regulator next year to carry out field tests of its HB4 wheat in Australia.
More information: Bioceres seeks approval to plant GM wheat in Australia
CORRECTION
In the last edition of GroundCoverTM, it was incorrectly stated that approximately 12,000 hectares of GM safflower are grown across Australia. This area includes both the GM and non-GM components of the crop.
The Agricultural Biotechnology Council of Australia is an industry initiative established to increase public awareness of, and encourage informed debate and decision-making about, gene technology