Expanding roles for S-nitrosylation in the regulation of plant immunity

Following pathogen recognition, plant cells produce a nitrosative burst resulting in a striking increase in nitric oxide (NO), altering the redox state of the cell, which subsequently helps orchestrate a plethora of immune responses. NO is a potent redox cue, efficiently relayed between proteins through its co-valent attachment to highly specific, powerfully reactive protein cysteine (Cys) thiols, resulting in formation of protein S-nitrosothiols (SNOs). This process, known as S-nitrosylation, can modulate the function of target proteins, enabling responsiveness to cellular redox changes. Key targets of S-nitrosylation control the production of reactive oxygen species (ROS), the transcription of immune-response genes, the triggering of the hypersensitive response (HR) and the establishment of systemic acquired resistance (SAR). Here, we bring together recent advances in the control of plant immunity by S-nitrosylation, furthering our appreciation of how changes in cellular redox status reprogramme plant immune function. [Display omitted] •S-nitrosylation is emerging as a key redox-based, post-translation modification.•Global protein S-nitrosylation is regulated indirectly by GSNOR and directly by TRXh5 during plant immune function.•Nitric oxide bioactivity modulates transcriptional and epigenetic mechanisms.•S-nitrosylation regulates SUMOylation during plant immunity.•Host directed S-nitrosylation blunts pathogen effector functions.