The NAC transcription factor ONAC083 negatively regulates rice immunity against Magnaporthe oryzae by directly activating transcription of the RING-H2 gene OsRFPH2-6.

NAC transcription factors play critical roles in plant immunity by modulating the expression of downstream genes via binding to specific cis-elements in promoters. Here, we report the function and regulatory network of a pathogen- and defense phytohormone-inducible NAC transcription factor gene, ONAC083, in rice (Oryza sativa) immunity. ONAC083 localizes to the nucleus and exhibited transcriptional activation activity that depended on its C-terminal region. Knockout of ONAC083 enhanced rice immunity against Magnaporthe oryzae, strengthened pathogen-induced defense responses, and boosted chitin-induced pattern-triggered immunity (PTI), whereas ONAC083 overexpression had the opposite effects. We identified ONAC083-binding sites in the promoters of 82 genes, and showed that ONAC083 specifically binds to a conserved element with the core sequence ACGCAA. ONAC083 activated the transcription of the genes OsRFPH2-6, OsTrx1, and OsPUP4 by directly binding to the ACGCAA element. OsRFPH2-6, encoding a RING-H2 protein with an N-terminal transmembrane region and a C-terminal typical RING domain, negatively regulated rice immunity against M. oryzae and chitin-triggered PTI. These data demonstrate that ONAC083 negatively contributes to rice immunity against M. oryzae by directly activating the transcription of OsRFPH2-6 through the ACGCAA element in its promoter. Overall, our study provides new insight into the molecular regulatory network of NAC transcription factors in rice immunity. This article is protected by copyright. All rights reserved.