GmEBS7a-E2 complex dissociation hyperactivates ERAD to impair plant immunity against Phytophthora pathogens

Abstract

Endoplasmic reticulum-associated degradation (ERAD) pathways are crucial for maintaining plant development and stress responses. While ERAD has been extensively studied for its role in regulating responses to abiotic stress, its specific manipulation by eukaryotic pathogens stress remains unclear. Here, we reported that soybean GmEBS7a, a plant-specific ERAD component, is targeted and stabilized by a transmembrane domain-containing effector Avh131 from Phytophthora sojae. GmEBS7a enhances plant disease susceptibility by increasing ERAD efficiency and ER stress sensitivity. Mechanistically, Avh131 competitively disrupts the interaction with GmEBS7a and the ubiquitin-conjugating enzyme GmUBC32, reducing ubiquitination of GmEBS7a and subsequent inhibition of its degradation. These findings demonstrate that excessive ERAD triggered by stabilized GmEBS7a and its partnering E3 ligase impairs the plants response to biotic stress. Our study uncovers a fine-tuning of the ER protein-folding capacity to promote infection, thereby expanding our understanding of ER-centered immunity during plant-pathogen interactions.