New research shows how plant immune receptors can evolve through molecular mimicry, opening a potential path to more durable disease resistance in cereal crops.
Scientists have found new evidence showing how plant immune receptors can evolve to recognize disease threats by mimicking the targets that pathogens attack.
Using this insight, researchers engineered a disease-resistance gene capable of recognizing two major crop pathogens. The discovery could help guide future efforts to develop crops with stronger and more durable resistance to disease.
International Research Effort
The study was led by scientists from The Sainsbury Laboratory and the John Innes Centre in Norwich, U.K., in collaboration with USDA–University of Minnesota laboratories in the U.S.
“This breakthrough discovery led by Diana Gómez de la Cruz and Matt Moscou has revealed how molecular mimicry can be used by plants to defend themselves against pathogen attack,” said Prof. Nick Talbot FRS, co-author and TSL's Executive Director. “Using the new tools of computational structural modelling, we have an opportunity to harness this discovery to develop completely new durable resistant crops in future. It is very exciting.”
A Major Threat to Cereal Crops
A major focus of the study is the blast fungus, Magnaporthe oryzae, one of the world’s most damaging plant pathogens. It infects several important cereal crops, including rice, wheat and barley. In rice alone, blast disease is estimated to destroy enough grain each year to feed about 60 million people, making it a serious and ongoing threat to global food security, according to a press release.
Building on Barley Resistance Research
The study builds on years of research in Matthew Moscou’s group at The Sainsbury Laboratory, now based at the USDA-ARS Cereal Disease Laboratory. First author Diana Gómez de la Cruz began the work during her PhD in the Moscou group and continued it as a postdoctoral researcher in Nick Talbot’s group at TSL.
An important starting point came from earlier TSL research on how barley recognizes the blast fungus. While working together in the Moscou group, Helen Brabham and Gómez de la Cruz showed that the barley immune receptor MLA3 helps provide resistance to M. oryzae by detecting Pwl2, a fungal effector protein secreted during infection. Read the paper here.
Understanding the Pathogen’s Strategy
At the same time, research led by Vincent Were in Nick Talbot’s group, together with Rafał Zdrzałek in Mark Banfield’s group at the John Innes Centre, showed that Pwl2 targets a specific plant protein during infection. By manipulating this protein, the fungus can weaken the plant’s defenses and support invasion.
Together, these findings gave researchers a starting point to study how the MLA3 immune receptor recognizes Pwl2 at the molecular level.
AlphaFold Reveals a Key Similarity
A major breakthrough came with AlphaFold, the artificial intelligence tool that transformed how scientists predict protein structures.
Gómez de la Cruz used AlphaFold to model how MLA3 and Pwl2 interact, helping the team better understand how the receptor recognizes the fungal effector. At the same time, Zdrzałek experimentally solved the structure of Pwl2 bound to its plant protein target.
When the predicted and experimental structures were compared, the similarity was striking. This led researchers to propose that MLA3 may recognize the pathogen by mimicking the same plant protein that the fungus is trying to attack.
Competing for the Same Target
During a seminar at The Sainsbury Laboratory, postdoctoral researcher Jack Rhodes asked whether the plant protein targeted by Pwl2 might affect how MLA3 recognizes the fungal effector. Follow-up experiments showed that it does: when the plant target protein was present, MLA3 was less able to recognize Pwl2. This suggested that the plant protein and MLA3 compete for the same binding site on the pathogen protein.
The results pointed to a new mechanism for crop disease resistance. MLA3 appears to have evolved to mimic the plant protein that Pwl2 targets during infection. By doing so, the immune receptor can intercept the fungal effector and trigger the plant’s defense response.
In effect, the receptor turns the pathogen’s own infection strategy against it. The finding provides direct evidence that plant immune receptors can evolve by mimicking pathogen targets, creating new ways to recognize disease threats.
A New Route for Engineering Resistance
This insight also opened the door to engineering broader crop disease resistance. After identifying the molecular surface that allows MLA3 to recognize Pwl2, researchers transferred that binding region into SR50, a related immune receptor found in rye.
SR50 naturally provides resistance to wheat stem rust, another major cereal disease. By adding the mimicry interface from the barley receptor, the team created a chimeric receptor capable of recognizing both stem rust and blast pathogens.
The work suggests that understanding how crop immune receptors recognize pathogens could help researchers design new resistance genes for cereals and other important crops.
The post Crop Disease Resistance Gene Targets Two Pathogens appeared first on Seed World.
New research shows how plant immune receptors can evolve through molecular mimicry, opening a potential path to more durable disease resistance in cereal crops.
Scientists have found new evidence showing how plant immune receptors can evolve to recognize disease threats by mimicking the targets that pathogens attack.
Using this insight, researchers engineered a disease-resistance gene capable of recognizing two major crop pathogens. The discovery could help guide future efforts to develop crops with stronger and more durable resistance to disease.
International Research Effort
The study was led by scientists from The Sainsbury Laboratory and the John Innes Centre in Norwich, U.K., in collaboration with USDA–University of Minnesota laboratories in the U.S.
“This breakthrough discovery led by Diana Gómez de la Cruz and Matt Moscou has revealed how molecular mimicry can be used by plants to defend themselves against pathogen attack,” said Prof. Nick Talbot FRS, co-author and TSL’s Executive Director. “Using the new tools of computational structural modelling, we have an opportunity to harness this discovery to develop completely new durable resistant crops in future. It is very exciting.”
A Major Threat to Cereal Crops
A major focus of the study is the blast fungus, Magnaporthe oryzae, one of the world’s most damaging plant pathogens. It infects several important cereal crops, including rice, wheat and barley. In rice alone, blast disease is estimated to destroy enough grain each year to feed about 60 million people, making it a serious and ongoing threat to global food security, according to a press release.
Building on Barley Resistance Research
The study builds on years of research in Matthew Moscou’s group at The Sainsbury Laboratory, now based at the USDA-ARS Cereal Disease Laboratory. First author Diana Gómez de la Cruz began the work during her PhD in the Moscou group and continued it as a postdoctoral researcher in Nick Talbot’s group at TSL.
An important starting point came from earlier TSL research on how barley recognizes the blast fungus. While working together in the Moscou group, Helen Brabham and Gómez de la Cruz showed that the barley immune receptor MLA3 helps provide resistance to M. oryzae by detecting Pwl2, a fungal effector protein secreted during infection. Read the paper here.
Understanding the Pathogen’s Strategy
At the same time, research led by Vincent Were in Nick Talbot’s group, together with Rafał Zdrzałek in Mark Banfield’s group at the John Innes Centre, showed that Pwl2 targets a specific plant protein during infection. By manipulating this protein, the fungus can weaken the plant’s defenses and support invasion.
Together, these findings gave researchers a starting point to study how the MLA3 immune receptor recognizes Pwl2 at the molecular level.
AlphaFold Reveals a Key Similarity
A major breakthrough came with AlphaFold, the artificial intelligence tool that transformed how scientists predict protein structures.
Gómez de la Cruz used AlphaFold to model how MLA3 and Pwl2 interact, helping the team better understand how the receptor recognizes the fungal effector. At the same time, Zdrzałek experimentally solved the structure of Pwl2 bound to its plant protein target.
When the predicted and experimental structures were compared, the similarity was striking. This led researchers to propose that MLA3 may recognize the pathogen by mimicking the same plant protein that the fungus is trying to attack.
Competing for the Same Target
During a seminar at The Sainsbury Laboratory, postdoctoral researcher Jack Rhodes asked whether the plant protein targeted by Pwl2 might affect how MLA3 recognizes the fungal effector. Follow-up experiments showed that it does: when the plant target protein was present, MLA3 was less able to recognize Pwl2. This suggested that the plant protein and MLA3 compete for the same binding site on the pathogen protein.
The results pointed to a new mechanism for crop disease resistance. MLA3 appears to have evolved to mimic the plant protein that Pwl2 targets during infection. By doing so, the immune receptor can intercept the fungal effector and trigger the plant’s defense response.
In effect, the receptor turns the pathogen’s own infection strategy against it. The finding provides direct evidence that plant immune receptors can evolve by mimicking pathogen targets, creating new ways to recognize disease threats.
A New Route for Engineering Resistance
This insight also opened the door to engineering broader crop disease resistance. After identifying the molecular surface that allows MLA3 to recognize Pwl2, researchers transferred that binding region into SR50, a related immune receptor found in rye.
SR50 naturally provides resistance to wheat stem rust, another major cereal disease. By adding the mimicry interface from the barley receptor, the team created a chimeric receptor capable of recognizing both stem rust and blast pathogens.
The work suggests that understanding how crop immune receptors recognize pathogens could help researchers design new resistance genes for cereals and other important crops.
The post Crop Disease Resistance Gene Targets Two Pathogens appeared first on Seed World.