Recommendations on terminology and experimental best practice associated with plant nitric oxide research

Abstract

Summary Nitric oxide (NO) emerged as a key signal molecule in plants. During the last two decades impressive progress has been made in plant NO research. This small, redox‐active molecule is now known to play an important role in plant immunity, stress responses, environmental interactions, plant growth and development. To more accurately and robustly establish the full spectrum of NO bioactivity in plants, it will be essential to apply methodological best practice. In addition, there are some instances of conflicting nomenclature within the field, which would benefit from standardization. In this context, we attempt to provide some helpful guidance for best practice associated with NO research and also suggestions for the cognate terminology.

An Update on Nitric Oxide Production and Role Under Phosphorus Scarcity in Plants

“…Nitric oxide may exert its biological functions through protein modifications, such as tyrosine nitration or S-nitrosation (also termed as S-nitrosylation), or through interaction with metalloproteins (metal-nitrosylation) (Figure 2), besides performing a broad spectrum of biochemical events through the interaction with hormones, and ROS among others (Gupta et al, 2020).…”

Glutathione‐dependent denitrosation of GSNOR1 promotes oxidative signalling downstream of H2O2

“…In addition to the roles of ROS, enhanced production of nitric oxide (NO) is a well‐documented response in plants subjected to many abiotic and biotic stresses (Fancy, Bahlmann, & Loake, ; Frederickson Matika & Loake, ; Scheler, Durner, & Astier, ). Redox effects of NO are thought to be mainly linked to protein S ‐nitrosation, an oxidative modification in which NO is covalently attached to a reactive protein cysteine (Cys) to form an S ‐nitrosothiol (SNO; Gupta et al, ). This process has been shown to alter protein conformation, DNA‐protein interactions, protein stability, and enzyme activities in plants and other eukaryotic organisms (Cui et al, ; Frungillo, Skelly, Loake, Spoel, & Salgado, ; Lindermayr, Sell, Müller, Leister, & Durner, ; Stomberski, Hess, & Stamler, ; Tada et al, ; Wang et al, ; Yun et al, ; Zhan et al, ).…”

Tracing the path of inhaled nitric oxide: Biological consequences of protein nitrosylation

“…Protein S ‐nitrosylation is a rapidly reversible and precisely targeted posttranslational modification, where NO covalently attaches to the thiol, an organic sulfhydryl group containing a sulfur‐hydrogen bond (–SH), on a cysteine amino acid to form a S ‐nitrosothiol (SNO), 9,10 a biologically active intermediate more stable than NO itself 11 . The more precise chemical term is nitrosation 12,13 ; but “nitrosylation” is commonly used 14,15 when describing its biological function. SNO can arise from endogenous or exogenous NO, from nitrite (exogenous or endogenous, usually derived from dietary nitrate) or other oxidized NO species, metal–NO complexes or protein nitrosothiols (R‐SNOs) 16 …”