The endoplasmic reticulum-quality control component SDF2 is essential for XA21-mediated immunity in rice

Plant genomes contain large number of plasma membrane (PM)-localized immune receptors, also called pattern recognition receptors (PRRs). PRRs are synthesized in the endoplasmic reticulum (ER) and then translocated to the PM, where they recognize conserved pathogen-associated molecular patterns (PAMPs) and activate innate immune response. The rice XA21 immune receptor confers resistance to the Gram-negative bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo). To identify components that mediate XA21-mediated signaling, we performed co-purification experiments using C-terminal GFP tagged XA21 protein. Several endoplasmic reticulum-quality control (ER-QC) proteins including stromal-derived factor 2 (SDF2) co-purified with XA21. Silencing of the SDF2 genes in the XA21 rice genetic background compromises resistance to Xoo but does not affect plant growth and development. (c) 2013 Elsevier Ireland Ltd. All rights reserved.