Crosstalk between nitric oxide and glutathione is required for NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1)-dependent defense signaling in Arabidopsis thaliana

New Phytol. 2015 Nov;208(3):860-72. doi: 10.1111/nph.13502. Epub 2015 Jun 10.


Nitric oxide (NO) is a ubiquitous signaling molecule involved in a wide range of physiological and pathophysiological processes in animals and plants. Although its significant influence on plant immunity is well known, information about the exact regulatory mechanisms and signaling pathways involved in the defense response to pathogens is still limited. We used genetic, biochemical, pharmacological approaches in combination with infection experiments to investigate the NO-triggered salicylic acid (SA)-dependent defense response in Arabidopsis thaliana. The NO donor S-nitrosoglutathione (GSNO) promoted the nuclear accumulation of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1) protein accompanied by an elevated SA concentration and the activation of pathogenesis-related (PR) genes, leading to induced resistance of A. thaliana against Pseudomonas infection. Moreover, NO induced a rapid change in the glutathione status, resulting in increased concentrations of glutathione, which is required for SA accumulation and activation of the NPR1-dependent defense response. Our data imply crosstalk between NO and glutathione, which is integral to the NPR1-dependent defense signaling pathway, and further demonstrate that glutathione is not only an important cellular redox buffer but also a signaling molecule in the plant defense response.

Keywords: Arabidopsis thaliana; NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1); defense response; glutathione (GSH); nitric oxide (NO); salicylic acid (SA).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / immunology
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism*
  • Disease Resistance*
  • Gene Expression Regulation, Plant
  • Glutathione / metabolism*
  • Nitric Oxide / metabolism*
  • Pseudomonas syringae
  • Receptor Cross-Talk
  • S-Nitrosoglutathione / metabolism
  • Salicylic Acid / metabolism
  • Signal Transduction


  • Arabidopsis Proteins
  • NPR1 protein, Arabidopsis
  • Nitric Oxide
  • S-Nitrosoglutathione
  • Glutathione
  • Salicylic Acid