Bioengineering a plant NLR immune receptor with a robust binding interface toward a conserved fungal pathogen...

Area of Science:

• Plant science
• Molecular biology
• Agricultural biotechnology

Background:

• Plant immune receptors, like nucleotide-binding, leucine-rich repeat (NLR) proteins, are crucial for disease resistance.
• Current methods for engineering plant immunity face challenges due to the rapid evolution of plant pathogens, limiting resistance durability.
• The rice NLR immune receptor Pik-1 recognizes effectors from the blast fungus *Magnaporthe oryzae*.

Purpose of the Study:

• To bioengineer the rice Pik-1 NLR immune receptor to recognize a conserved family of effectors from the multihost blast fungus pathogen *Magnaporthe oryzae*.
• To enhance the durability and breadth of plant disease resistance against evolving pathogens.

Main Methods:

• Engineered the Pik-1 NLR receptor by replacing its native integrated heavy metal-associated domain with a putative host target, OsHIPP43.
• Created a chimeric receptor, Pikm-1^OsHIPP43, to alter its effector binding and response profile.
• Determined the crystal structure of the Pwl2/OsHIPP43 complex to analyze the interaction interface.

Main Results:

• The engineered Pikm-1^OsHIPP43 receptor successfully recognized the host-determining factor Pwl2, an effector from *Magnaporthe oryzae*.
• The chimeric receptor also responded to other PWL alleles from diverse blast isolates, indicating broad recognition.
• Structural analysis revealed a robust and multifaceted interface between Pwl2 and OsHIPP43, suggesting resistance to mutational disruption.

Conclusions:

• Bioengineering plant immune receptors by targeting pathogen effectors' host targets can create recognition specificities with enhanced durability and breadth.
• This strategy offers a promising alternative to naturally evolved resistance genes for more robust crop protection against plant pathogens.
• The findings pave the way for developing durable, broad-spectrum resistance in crops against devastating diseases like rice blast.