ABSTRACT
Plant innate immunity is mediated by pattern recognition receptors (PRRs) and intracellular NB-LRR (nucleotide-binding domain and leucine-rich repeat) proteins. Overexpression of the endoplasmic reticulum (ER) chaperone, luminal-binding protein 3 (BiP3) compromises resistance to Xanthomonas oryzae pv. oryzae (Xoo) mediated by the rice PRR XA21 (Park et al., PLoS ONE 5(2): e9262). Here we show that BiP3 overexpression also compromises resistance mediated by rice XA3, a PRR that provides broad-spectrum resistance to Xoo. In contrast, BiP3 overexpression has no effect on resistance mediated by rice Pi5, an NB-LRR protein that confers resistance to the fungal pathogen Magnaporthe oryzae (M. oryzae). Our results suggest that rice BiP3 regulates membrane-resident PRR-mediated immunity.
Footnotes
List of abbreviations: ER, endoplasmic reticulum; BiP3, luminal-binding protein 3; BRI1, brassinosteroid-insensitive 1; EFR, elongation factor Tu receptor; FLS2, flagellin sensitive 2; HSP70, heat shock protein 70; M. oryzae, Magnaporthe oryzae; NB-LRR, nucleotide-binding domain and leucine-rich repeat; non-RD, non-arginine-aspartate; PRR, pattern recognition receptor; XA21, Xanthomonas resistance 21 receptor; Xoo, Xanthomonas oryzae pv. oryzae