A PR1-Like Protein Stabilizes a Barwin-Like Protein to Enhance Wheat Resistance to Leaf Rust

Area of Science:

• Plant Pathology
• Molecular Plant-Microbe Interactions
• Wheat Molecular Genetics

Background:

• Pathogenesis-related 1 (PR1) proteins are key components of plant immune responses, exhibiting antimicrobial activity and regulating protein stability.
• TaPR1-2 is a known marker for wheat immunity against rust fungi, but the roles of other PR1 family members in leaf rust resistance are largely unknown.

Purpose of the Study:

• To investigate the role of TaPR1-11 in wheat resistance to leaf rust caused by Puccinia triticina (Pt).
• To elucidate the molecular mechanism underlying TaPR1-11's function in wheat defense.

Main Methods:

• Gene expression analysis of TaPR1-11 upon Pt inoculation.
• Wheat transformation for TaPR1-11 overexpression and RNA interference (RNAi).
• Yeast two-hybrid assays and co-immunoprecipitation to study protein-protein interactions.
• In vivo protein stabilization assays.

Main Results:

• TaPR1-11 transcript levels were induced following Pt inoculation.
• Overexpression of TaPR1-11 enhanced wheat resistance to Pt, reducing fungal growth.
• TaPR1-11-RNAi lines showed increased susceptibility to Pt.
• TaPR1-11 physically interacts with TaPR4-1, a positive regulator of wheat resistance.
• TaPR1-11 stabilizes TaPR4-1, and TaPR4-1 reciprocally promotes TaPR1-11 accumulation during infection.

Conclusions:

• TaPR1-11 plays a significant role in enhancing wheat resistance to leaf rust.
• A novel PR1-PR4 protein partnership, where TaPR1-11 stabilizes TaPR4-1, is identified.
• This interaction is crucial for effective defense responses against Puccinia triticina in wheat.