S-nitrosylation of the zinc finger protein SRG1 regulates plant immunity

Beimi Cui, Qiaona Pan, David Clarke, Marisol Ochoa Villarreal, Saima Umbreen, Bo Yuan, Weixing Shan, Jihong Jiang, Gary J. Loake*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Nitric oxide (NO) orchestrates a plethora of incongruent plant immune responses, including the reprograming of global gene expression. However, the cognate molecular mechanisms remain largely unknown. Here we show a zinc finger transcription factor (ZF-TF), SRG1, is a central target of NO bioactivity during plant immunity, where it functions as a positive regulator. NO accumulation promotes SRG1 expression and subsequently SRG1 occupies a repeated canonical sequence within target promoters. An EAR domain enables SRG1 to recruit the corepressor TOPLESS, suppressing target gene expression. Sustained NO synthesis drives SRG1 S-nitrosylation predominantly at Cys87, relieving both SRG1 DNA binding and transcriptional repression activity. Accordingly, mutation of Cys87 compromises NO-mediated control of SRG1-dependent transcriptional suppression. Thus, the SRG1-SNO formation may contribute to a negative feedback loop that attenuates the plant immune response. SRG1 Cys87 is evolutionary conserved and thus may be a target for redox regulation of ZF-TF function across phylogenetic kingdoms.

Original languageEnglish
Article number4226
Number of pages12
JournalNature Communications
Volume9
Early online date12 Oct 2018
DOIs
Publication statusPublished - 12 Oct 2018

Keywords

  • NITRIC-OXIDE
  • NITROSATIVE STRESS
  • DISEASE RESISTANCE
  • CELL-DEATH
  • TRANSCRIPTION FACTORS
  • ARABIDOPSIS-THALIANA
  • GENE-EXPRESSION
  • EAR-MOTIF
  • NITROSOGLUTATHIONE REDUCTASE
  • DEFENSE RESPONSES

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