S-nitrosothiols regulate nitric oxide production and storage in plants through the nitrogen assimilation pathway.
Nitrogen assimilation plays a vital role in plant metabolism. Assimilation of nitrate, the primary source of nitrogen in soil, is linked to the generation of the redox signal nitric oxide (NO). An important mechanism by which NO regulates plant development and stress responses is through S-nitrosylation, that is, covalent attachment of NO to cysteine residues to form S-nitrosothiols (SNO). Despite the importance of nitrogen assimilation and NO signalling, it remains largely unknown how these pathways are interconnected. Here we show that SNO signalling suppresses both nitrate uptake and reduction by transporters and reductases, respectively, to fine tune nitrate homeostasis. Moreover, NO derived from nitrate assimilation suppresses the redox enzyme S-nitrosoglutathione Reductase 1 (GSNOR1) by S-nitrosylation, preventing scavenging of S-nitrosoglutathione, a major cellular bio-reservoir of NO. Hence, our data demonstrates that (S)NO controls its own generation and scavenging by modulating nitrate assimilation and GSNOR1 activity.
Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, CP 6109, Campinas-SP 13083-970, Brazil.
Lucas
L
Frungillo
Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK.
Michael J
MJ
Skelly
Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK.
Gary J
GJ
Loake
Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK.
Steven H
SH
Spoel
Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, CP 6109, Campinas-SP 13083-970, Brazil.
Ione
I
Salgado
D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006706:Homeostasis / Q000502:physiology; D008954:Models, Biological; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D026403:S-Nitrosothiols / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
D029681:Arabidopsis Proteins; D009566:Nitrates; D026403:S-Nitrosothiols; D009569:Nitric Oxide; D005980:Glutathione Reductase; C521253:S-nitrosoglutathione reductase, Arabidopsis; D009584:Nitrogen