title: AIR12, a b-type cytochrome of the plasma membrane of Arabidopsis thaliana is a negative regulator of resistance against Botrytis cinerea.
abstract: AIR12 (Auxin Induced in Root culture) is a single gene of Arabidopsis that codes for a mono-heme cytochrome b. Recombinant AIR12 from Arabidopsis accepted electrons from ascorbate or superoxide, and donated electrons to either monodehydroascorbate or oxygen. AIR12 was found associated in vivo to the plasma membrane. Though linked to the membrane by a glycophosphatidylinositol anchor, AIR12 is a hydrophilic and glycosylated protein predicted to be fully exposed to the apoplast. The expression pattern of AIR12 in Arabidopsis is developmentally regulated and correlated to sites of controlled cell separation (e.g. micropilar endosperm during germination, epidermal cells surrounding the emerging lateral root) and cells around wounds. Arabidopsis (Landsberg erecta-0) mutants with altered levels of AIR12 did not show any obvious phenotype. However, AIR12-overexpressing plants accumulated ROS (superoxide, hydrogen peroxide) and lipid peroxides in leaves, indicating that AIR12 may alter the redox state of the apoplast under particular conditions. On the other hand, AIR12-knock out plants displayed a strongly decreased susceptibility to Botrytis cinerea infection, which in turn induced AIR12 expression in susceptible wild type plants. Altogether, the results suggest that AIR12 plays a role in the regulation of the apoplastic redox state and in the response to necrotrophic pathogens. Possible relationships between these functions are discussed.
authors.affiliation: Dipartimento di Bioscienze, Università di Milano, Via G. Celoria 24, 20133 Milano, Italy.
authors.forename: Alex
authors.initials: A
authors.lastname: Costa
authors.affiliation: Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Irnerio 42, 40126 Bologna, Italy.
authors.forename: Maria Raffaella
authors.initials: MR
authors.lastname: Barbaro
authors.affiliation: Dipartimento di Biologia e Biotecnologia "C. Darwin," Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza Università di Roma, 00185 Roma, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Sicilia
authors.affiliation: Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Irnerio 42, 40126 Bologna, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Preger
authors.affiliation: Commissariat à l'Energie Atomique et aux énergies alternatives (CEA) Saclay, Institut de Biologie et Technologie de Saclay, Centre National de la Recherche Scientifique UMR 8221, 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Anja
authors.initials: A
authors.lastname: Krieger-Liszkay
authors.affiliation: Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Irnerio 42, 40126 Bologna, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Sparla
authors.affiliation: Dipartimento di Biologia e Biotecnologia "C. Darwin," Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza Università di Roma, 00185 Roma, Italy. Electronic address: giulia.delorenzo@uniroma1.it.
authors.forename: Giulia
authors.initials: G
authors.lastname: De Lorenzo
authors.affiliation: Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Via Irnerio 42, 40126 Bologna, Italy. Electronic address: paolo.trost@unibo.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Trost
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D020171:Botrytis / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D003573:Cytochrome b Group / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology
chemical_list: C515034:AIR9 protein, Arabidopsis; D029681:Arabidopsis Proteins; D003573:Cytochrome b Group; D008869:Microtubule-Associated Proteins
keywords: Apoplast; Ascorbate; Botrytis cinerea; Cytochrome b; Plasma membrane redox; Reactive oxygen species