Proteasomal degradation of JAZ9 by SALT- AND DROUGHT-INDUCED RING FINGER1 during pathogen infection.

E3 ubiquitin ligase SALT- AND DROUGHT-INDUCED RING FINGER1 (SDIR1) plays a novel role in modulating plant immunity against pathogens. The molecular interactors of SDIR1 during pathogen infection are not known. SDIR1 interacting Jasmonate ZIM-domain (JAZ) proteins were identified through a yeast two-hybrid (Y2H) screen. Full length JAZ9 interacts with SDIR1 only in the presence of coronatine, a bacteria secreted toxin, or jasmonic acid (JA) in Y2H assay. The bi-molecular fluorescence complementation and pull-down assays confirm the in planta interaction of these proteins. JAZ9 proteins, negative regulators of JA-mediated plant defense, were degraded during the pathogen infection by SDIR1 through a proteasomal pathway causing disease susceptibility against hemibiotrophic pathogens.