A UK-led research collaboration has taken a significant step in the global effort to protect cereal crops from the devastating blast fungus pathogen.
Researchers at the John Innes Centre explored a recently discovered class of plant defence receptors, showing at molecular level how they function to limit blast pathogen attacks and how they might be bioengineered to introduce broader more durable immunity into wheat, barley, and rice.
“We’ve discovered something that could lead to a potential intervention on what is the worst fungal disease of cereals,” said Professor Mark Banfield, a group leader at the John Innes Centre an author of the study which was carried out in association with researchers at Kobe University, Japan.
The blast fungus, Magnaporthe oryzae, is the most serious disease of cultivated rice and has spread to wheat and barley in parts of Asia and Africa, meaning that innovative solutions to prevent it are essential to global food security.
To infect plants, pathogens such as Magnaporthe oryzae insert effectors into leaf and stem cells to manipulate the host and promote disease.
Plants have receptors which recognise effectors as foreign molecules and prompt an immune response that initiates localised cell death to limit the intracellular spread of the pathogen throughout the plant.
For more than 30 years a considerable body of research has focused on a class of immune receptors called Nucleotide-binding and leucine-rich receptors (NLRs) which have been at the forefront of our understanding of plant immunity response to blast and other diseases.
In recent years, studies have increasingly focused on a new class of intracellular immune receptors discovered in cereals called tandem kinase proteins (TKPs).
Previous research has shown that TKPs can contain an integrated Heavy Metal Associated (HMA) domain, a feature also seen in some NLR receptors, and which has been shown to be important for effector recognition and mounting an immune response.
“This piqued our interest,” said Professor Banfield. “If we can engineer these integrated HMA domains for new properties by making amino acid protein changes where effectors bind, we can gain what we call novel recognition specificities – and potentially a new frontline for defence of plants against disease.”
In this study, which appeared in Science Advances , the group used biophysical analysis and crystallography to reveal at high resolution the structural interaction between HMA domains and blast pathogen effectors.
They show how HMA domains play a critical role in TKPs by acting as biological baits to lure pathogen effectors.
Using the structural knowledge, they successfully bioengineered TKP immune receptors so that they had dual specificity – binding to effectors associated with infection of both wheat and barley, something that does not happen often in nature.
By demonstrating that TKPs were amenable to bioengineering approaches, the study sets the stage for further research into many recently discovered TKPs in diverse cereal crops, with the potential for custom-engineering new disease resistance receptors which respond to multiple effectors simultaneously.
These proof of principle experiments used protoplasts, individual wheat cells as surrogates of whole plant tissue. The next stage for this group is to translate these findings from surrogate assays into glasshouse plants.
“Our study indicates that this new class of resistance proteins is amenable for engineering purposes. We now know that the previous tools we used in engineering NLR receptors may also work with this new class,” said Dr. Daniel Yu, the first author of the study.
The fundamental understanding of effector-receptor binding may be augmented by other technologies such as precision breeding and AI approaches - which can help bioengineer novel specificity into HMA domains.
“We think these two classes of immune receptors, NLRs and TKPs, are probably activated in different ways,” said Professor Banfield. “That gives the potential for more robust immunity in the field because you are not putting all your eggs in one basket. Further down the road we may be able to use techniques to stack genes encoding TKPs and NLRs together against the same disease, making a super-resistant crop. They will have different ways of activating immunity, so it is likely to be more difficult for a pathogen to evolve away from,” he added.
Each year blast claims enough rice to feed 60 million people . In wheat, the blast fungus was first discovered in Brazil in the 1980s and has spread to Asia and Africa since. It is not in the UK, but changing climate means that it could eventually pose a threat to cereal production in northern Europe.
Engineering plant tandem kinase immune receptors expands effector recognition profiles, appears in Science Advances
Science Advances
Experimental study
Cells
Engineering plant tandem kinase immune receptors expands effector recognition profiles
23-Sep-2026