Gluing rice E3 ligase and pathogen effector for disease control.

Area of Science:

• Plant pathology
• Molecular biology
• Biochemistry

Background:

• The rice blast fungus (Magnaporthe oryzae) poses a significant threat to global rice production.
• Fungal effectors, such as AVR-PikC, are key virulence factors that manipulate host processes.
• AVR-PikC interacts with rice proteins, potentially contributing to disease susceptibility.

Purpose of the Study:

• To investigate the molecular mechanisms underlying AVR-PikC function in rice.
• To identify strategies for enhancing rice resistance against the blast fungus.
• To explore the potential of small molecules in modulating plant-pathogen interactions.

Main Methods:

• Yeast three-hybrid assays to detect protein-protein interactions.
• Co-immunoprecipitation to confirm interactions in planta.
• Ubiquitination assays to assess protein modification.
• Degradation assays to monitor protein turnover.
• Phenotypic analysis of rice plants treated with B93.

Main Results:

• The rice protein HIPP19 was identified as a binding partner of AVR-PikC, potentially mediating susceptibility.
• The compound B93 was found to induce an interaction between AVR-PikC and the rice E3 ligase APIP6.
• This induced interaction led to the ubiquitination and subsequent degradation of AVR-PikC.
• Degradation of AVR-PikC resulted in enhanced resistance of rice plants to the blast fungus.

Conclusions:

• The AVR-PikC-HIPP19 interaction is a potential target for modulating rice susceptibility.
• The small molecule B93 effectively targets AVR-PikC for degradation via the APIP6 E3 ligase.
• This study presents a novel strategy for engineering durable resistance in rice against the blast pathogen.