title: Local root apex hypoxia induces NO-mediated hypoxic acclimation of the entire root.
abstract: Roots are very sensitive to hypoxia and adapt effectively to a reduced availability of oxygen in the soil. However, the site of the root where oxygen availability is sensed and how roots acclimate to hypoxia remain unclear. In this study, we found that the root apex transition zone plays central roles in both sensing and adapting to root hypoxia. The exposure of cells of the root apex to hypoxia is sufficient to achieve hypoxic acclimation of the entire root; particularly relevant in this respect is that, of the entire root apex, the transition zone cells show the highest demand for oxygen and also emit the largest amount of nitric oxide (NO). Local root apex-specific oxygen deprivation dramatically inhibits the oxygen influx peak in the transition zone and simultaneously stimulates a local increase in NO emission. The hypoxia-induced efflux of NO is strictly associated with the transition zone and is essential for hypoxic acclimation of the entire root.
authors.affiliation: LINV, Department of Plant, Soil and Environmental Science, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, FI, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Mugnai
authors.forename: Elisa
authors.initials: E
authors.lastname: Azzarello
authors.forename: Frantisek
authors.initials: F
authors.lastname: Baluska
authors.forename: Stefano
authors.initials: S
authors.lastname: Mancuso
mesh_terms: D000064:Acclimatization / Q000187:drug effects*; D000426:Alcohol Dehydrogenase / Q000378:metabolism; D001565:Benzoates / Q000494:pharmacology; D015687:Cell Hypoxia / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D018519:Meristem / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D008954:Models, Biological; D009569:Nitric Oxide / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010100:Oxygen / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D003313:Zea mays / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*
chemical_list: D001565:Benzoates; D016166:Free Radical Scavengers; D007093:Imidazoles; D020030:Nitric Oxide Donors; D011768:Pyruvate Dehydrogenase Complex; C079393:1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole; D009599:Nitroprusside; D009569:Nitric Oxide; D026423:S-Nitroso-N-Acetylpenicillamine; D000426:Alcohol Dehydrogenase; D010100:Oxygen