title: Negative Regulation of Autophagy by Sulfide Is Independent of Reactive Oxygen Species.
abstract: Accumulating experimental evidence in mammalian, and recently plant, systems has led to a change in our understanding of the role played by hydrogen sulfide in life processes. In plants, hydrogen sulfide mitigates stress and regulates important plant processes such as photosynthesis, stomatal movement, and autophagy, although the underlying mechanism is not well known. In this study, we provide new experimental evidence that, together with our previous findings, demonstrates the role of hydrogen sulfide in regulating autophagy. We used green fluorescent protein fluorescence associated with autophagic bodies and immunoblot analysis of the ATG8 protein to show that sulfide (and no other molecules such as sulfur-containing molecules or ammonium) was able to inhibit the autophagy induced in Arabidopsis (Arabidopsis thaliana) roots under nitrogen deprivation. Our results showed that sulfide was unable to scavenge reactive oxygen species generated by nitrogen limitation, in contrast to well-established reducers. In addition, reducers were unable to inhibit the accumulation of autophagic bodies and ATG8 protein forms to the same extent as sulfide. Therefore, we conclude that sulfide represses autophagy via a mechanism that is independent of redox conditions.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, 41092 Seville, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Laureano-Marín
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, 41092 Seville, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Moreno
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, 41092 Seville, Spain.
authors.forename: Luis C
authors.identifier: 0000-0002-2414-4813
authors.initials: LC
authors.lastname: Romero
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, 41092 Seville, Spain gotor@ibvf.csic.es.
authors.forename: Cecilia
authors.identifier: 0000-0003-4272-7446
authors.initials: C
authors.lastname: Gotor
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects*; D000071190:Autophagy-Related Protein 8 Family / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015151:Immunoblotting; D009584:Nitrogen / Q000378:metabolism; D010641:Phenotype; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D013440:Sulfides / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism
chemical_list: C000597073:ATG8 protein, Arabidopsis; D000975:Antioxidants; D029681:Arabidopsis Proteins; D000071190:Autophagy-Related Protein 8 Family; D017382:Reactive Oxygen Species; D013440:Sulfides; D013481:Superoxides; D049452:Green Fluorescent Proteins; D006861:Hydrogen Peroxide; D005978:Glutathione; D009584:Nitrogen