Two complementary NLRs from wild emmer wheat confer powdery mildew resistance

Area of Science:

• Plant Pathology
• Genetics
• Molecular Biology

Background:

• Powdery mildew significantly reduces global wheat yield and quality.
• Understanding genetic resistance mechanisms is crucial for crop improvement.

Purpose of the Study:

• To identify and characterize novel genetic loci conferring resistance to powdery mildew in wheat.
• To elucidate the molecular basis of resistance mediated by the identified locus.

Main Methods:

• Map-based cloning and mutagenesis were employed to isolate the resistance locus.
• Stable genetic transformation and gene expression studies were conducted.
• Protein-protein interaction assays were performed.

Main Results:

• A novel powdery mildew resistance locus, MlIW39, was identified from wild emmer wheat.
• MlIW39 resistance is conferred by a pair of complementary nucleotide-binding and leucine-rich repeat (NLR) genes: MlIW39-R1 (coiled-coil type NLR) and MlIW39-R2 (atypical NLR).
• The NLR pair, but not individual genes, induces cell death in model plants, and the proteins physically interact.

Conclusions:

• The study highlights the importance of NLR gene pairs in plant immunity.
• The findings facilitate wheat disease-resistance breeding through MlIW39 introgression lines and functional markers.