Interference between Two Specific Pathogen Recognition Events Mediated by Distinct Plant Disease Resistance Genes

Area of Science:

• Plant immunity
• Molecular plant-pathogen interactions
• Arabidopsis thaliana genetics

Background:

• Plant immune receptors recognize pathogen effectors to trigger defense.
• The avirulence proteins AvrRpt2 and AvrRpm1 are recognized by plant resistance proteins RPS2 and RPM1, respectively.
• Cross-talk between plant immune pathways can modulate disease resistance.

Purpose of the Study:

• To investigate the interaction between the Arabidopsis thaliana RPS2 and RPM1 resistance pathways.
• To determine the mechanism and consequences of interference between these two plant immune signaling pathways.

Main Methods:

• Bacterial genetics using Pseudomonas syringae strains expressing different avirulence genes.
• Arabidopsis thaliana genetic analysis involving RPS2 and RPM1.
• Analysis of gene expression during plant-pathogen interactions.

Main Results:

• The RPS2-AvrRpt2 interaction interferes with the RPM1-AvrRpm1 interaction in Arabidopsis.
• This interference occurs outside the bacterial pathogen and does not require functional RPS2.
• High levels of AvrRpm1 can overcome the interference, and transcriptional changes reflect activation of both RPS2 and RPM1 pathways.

Conclusions:

• Plant resistance proteins can interfere with each other's function, suggesting competition for signaling components.
• This interference impacts the plant's overall disease resistance response.
• Understanding these interactions is crucial for deciphering complex plant immune signaling networks.