title: The defence elicitor AsES causes a rapid and transient membrane depolarization, a triphasic oxidative burst and the accumulation of nitric oxide.
abstract: The newly characterized elicitor AsES obtained from Acremonium strictum induces a strong defence response in strawberry plants and confers plants resistance against the fungal pathogen Colletotricum acutatum the casual agent of anthracnose disease. Previous studies showed that AsES causes the accumulation of reactive oxygen species (ROS) that peaked 4 h post treatment (hpt), but due to the experimental approach used it was not clear whether the accumulation of ROS observed was intracellular or extracellular or took place as a single peak. By using a different experimental setup, a more complex early events associated to the activation of the innate immunity were observed. In this paper we report that strawberry plant cells treated with AsES exhibits a triphasic production of H2O2 and a rapid intracellular accumulation of NO. The first phase consists in a progressive extracellular accumulation of H2O2 that starts immediately after the treatment with AsES and is preceded by a rapid and transient cell membrane depolarization. During this phase takes place also a rapid intracellular accumulation of NO. Microscopic observations of mesophyll cells treated with AsES reveals that NO accumulates at the chloroplast. After the first extracellular H2O2 production phase, two intracellular H2O2 accumulation events occur, the first 2 hpt, and the second 7 hpt. Cells treated with AsES also show a transient increase of ion leakage, and a progressive alkalinization of the extracellular medium.
authors.affiliation: Instituto Superior de Investigaciones Biológicas (INSIBIO), Conicet-Universidad Nacional de Tucumán, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI Tucumán, Argentina.
authors.forename: Gustavo Gabriel
authors.initials: GG
authors.lastname: Martos
authors.affiliation: Instituto Superior de Investigaciones Biológicas (INSIBIO), Conicet-Universidad Nacional de Tucumán, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI Tucumán, Argentina.
authors.forename: María Del Milagro
authors.initials: Mdel M
authors.lastname: Terán
authors.affiliation: Instituto Superior de Investigaciones Biológicas (INSIBIO), Conicet-Universidad Nacional de Tucumán, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI Tucumán, Argentina. Electronic address: juan@fbqf.unt.edu.ar.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Díaz Ricci
mesh_terms: D000164:Acremonium / Q000737:chemistry*; D000468:Alkalies / Q000378:metabolism; D001190:Arylsulfonates / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D019069:Cell Respiration / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005453:Fluorescence; D031985:Fragaria / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005656:Fungal Proteins / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D007477:Ions; D008564:Membrane Potentials / Q000187:drug effects*; D058503:Mesophyll Cells / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D016897:Respiratory Burst / Q000187:drug effects*; D013535:Suspensions; D013997:Time Factors
chemical_list: D000468:Alkalies; D001190:Arylsulfonates; D005656:Fungal Proteins; D007477:Ions; D013535:Suspensions; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; C005047:pyranine
keywords: Elicitor; Innate immunity; Oxidative burst; Strawberry