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“Killer” fungal gene could provide key to wheat disease control
A specific gene appears to protect some fungal threats as they invade wheat. Disarming these defences could offer a pathway to keeping pathogens in check
10 January, 2025
A critical gene that leads to the synthesis of a protein known as Knr4 could be the key to what makes some fungal pathogens so virulent. Focusing prevention strategies on disabling or modifying this gene or the protein it encodes for, could provide new pathways for disease control.
In a newly published study, scientists at Rothamsted Research, in partnership with the University of Bath and the University of Exeter, used combined pathogen host modelling to map the cereal disease Fusarium interaction for the first time. This modelling looks at the genes that are active during infection and traces them to proteins that drive infection.
Starting with a genome of over 14,000 genes, this targeted approach identified the protein Knr4 as a critical driver of infection for Fusarium Head Blight (FHB) and Septoria tritici blotch (STB) – two of the most common diseases of wheat. Knr4 is involved in regulating growth rate and sensitivity to stress, and appears to be necessary for full Fusarium virulence.
Knocking the gene out in Fusarium saw a complete inability of the pathogen to spread in the wheat spike and a similar deletion also resulted in a drop in virulence of Septoria.
“This protein is only found in fungi, not in plants or animals,” said Dr Erika Kroll, who led the study. “This means that if we target Knr4, we may be able to reduce the infectivity of pathogenic fungi without harming the wheat crop, ourselves, or other animals. This could be a game-changer for controlling these serious pathogens.”
Kroll believes that this gene discovery approach is best thought of as exploring a city map, where roads connect key locations like houses, stores, workplaces and recreation areas. In a biological network, the connections represent interactions between genes. Just as some intersections in a city are critical for traffic flow, certain genes serve as crucial "hubs" in the fungal network. If one of these essential genes is disrupted, such as Knr4, the network collapses, halting the fungus's ability to survive and spread.
The five highest global contributors to wheat yield and quality losses are all fungal diseases and include Fusarium Head Blight disease (FHB) and Septoria tritici blotch disease (STB), which each account for around 2-3% of wheat losses globally. With mounting challenges in fungal control and increasing restrictions on fungicide use due to environmental concerns, there is an urgent need for innovative control strategies.
This could be achieved through the development of chemical fungicides that disrupt the protein's function or through the application of RNA interference techniques that would reduce fungal gene expression. Stricter regulation of fungicides is contributing to growing pathogen resistance as fewer chemicals can be used for control.
“There is a pressing need to identify new target sites for control. This research not only advances our understanding of mechanisms required for full fungal virulence but also offers promising directions for the development of effective strategies for disease control in agriculture,” said Kroll.
The Knr4 gene was originally explored in the model yeast fungus Saccharomyces cerevisiae and was named Knr4 which is short for "killer nine resistant". This is because overexpression of the Knr4 gene in this yeast species was found to be associated with resistance to the killer nine toxin produced by a wild yeast species.
Publication
Contacts
Erika Kroll
WHEAT PATHOGENOMICS
Dr Kim Hammond-Kosack
Molecular Plant Pathologist
Dr Martin Urban
Data Scientist
ABOUT ROTHAMSTED RESEARCH
Rothamsted Research is the longest-running agricultural research institute in the world. We work from gene to field with a proud history of ground-breaking
discoveries in areas as diverse as crop management, statistical interpretation and soil health. Our founders, in 1843, were the pioneers of modern
agriculture, and we are known for our imaginative science and our collaborative approach to developing innovative farm practice.
Through independent research, we make significant contributions to improving agri-food systems in the UK and internationally, with
economic impact estimated to exceed £3 bn in annual contribution to the UK economy. Our strength lies in our systems approach, which combines strategic research,
interdisciplinary teams and multiple partnerships.
Rothamsted is home to three unique National Bioscience Research Infrastructures which are open to researchers from all over the world:
The Long-Term Experiments,
Rothamsted Insect Survey and the
North Wyke Farm Platform.
We are strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC), with additional support from other national and
international funding streams, and from industry. We are also supported by the Lawes Agricultural Trust (LAT).
ABOUT BBSRC
The Biotechnology and Biological Sciences Research Council is part of UK Research and Innovation, a non-departmental public body funded by a grant-in-aid
from the UK government.
BBSRC invests to push back the frontiers of biology and deliver a healthy, prosperous and sustainable future. Through our investments, we build and support a vibrant,
dynamic and inclusive community which delivers ground-breaking discoveries and develops bio-based solutions that contribute to tackling global challenges,
such as sustainable food production, climate change, and healthy ageing.
As part of UK Research and Innovation (UKRI), we not only play a pivotal role in fostering connections that enable the UK’s world-class research and innovation system
to flourish – we also have a responsibility to enable the creation of a research culture that is diverse, resilient, and engaged.
BBSRC proudly forges interdisciplinary collaborations where excellent bioscience has a fundamental role. We pioneer approaches that enhance the equality, diversity,
and inclusion of talent by investing in people, infrastructure, technologies, and partnerships on a global scale.
ABOUT LAT
The Lawes Agricultural Trust, established in 1889 by Sir John Bennet Lawes, supports Rothamsted Research’s national and international agricultural science through the provision of land, facilities and funding. LAT, a charitable trust, owns the estates at Harpenden and Broom's Barn, including many of the buildings used by Rothamsted Research. LAT provides an annual research grant to the Director, accommodation for nearly 200 people, and support for fellowships for young scientists from developing countries. LAT also makes capital grants to help modernise facilities at Rothamsted, or invests in new buildings.