title: New insights on the barrel medic MtOGG1 and MtFPG functions in relation to oxidative stress response in planta and during seed imbibition.
abstract: In plants, 8-oxoguanine DNA glycosylase/lyase (OGG1) and formamidopyrimidine-DNA glycosylase (FPG) play similar roles within the base excision repair (BER) pathway involved in the removal of oxidized bases, e.g. 7,8-dihydro-8-oxoguanine (8-oxo-dG) and formamidopyrimidine (FAPy) lesions. To date, it is not clear why plants have retained both the OGG1 and FPG functions. In the present work, we have investigated the possible roles played in planta by MtOGG1 and MtFPG genes from Medicago truncatula Gaertn. (barrel medic). Bioinformatic investigation revealed the presence of putative mitochondrial and nuclear localization signals in the MtOGG1 and MtFPG amino acid sequences, respectively, thus suggesting for different subcellular fates. The expression profiles of both genes were evaluated by Quantitative Real-Time PCR (QRT-PCR) in barrel medic plantlets grown in vitro under oxidative stress conditions induced by copper (CuCl(2), 0.05, 0.1 and 0.2 mM) and polyethylene glycol (PEG6000, 50, 100 and 150 g L(-1)). The MtOGG1 and MtFPG genes were up-regulated in response to stress agents, at different levels, depending on treatment and tissue. As for copper, MtOGG1 showed significant up-regulation (up to 1.2- and 1.7-fold) only in roots while the MtFPG mRNA significantly increased (up to 1.3- and 2.8-fold, respectively) in roots and aerial parts. In response to PEG, the MtOGG1 expression was significantly enhanced in aerial parts (up to 1.3-fold) while the MtFPG showed significant (1.2-fold) up-regulation in roots. The expression profiles of MtOGG1 and MtFPG genes were also evaluated during seed imbibition, a physiological process which is characterized by Reactive Oxygen Species (ROS) accumulation and requires active DNA repair.
authors.affiliation: Dipartimento di Genetica e Microbiologia, via Ferrata 1, 27100 Pavia, Italy.
authors.forename: Anca
authors.initials: A
authors.lastname: Macovei
authors.forename: Alma
authors.initials: A
authors.lastname: Balestrazzi
authors.forename: Massimo
authors.initials: M
authors.lastname: Confalonieri
authors.forename: Matteo
authors.initials: M
authors.lastname: Faé
authors.forename: Daniela
authors.initials: D
authors.lastname: Carbonera
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology; D002467:Cell Nucleus / Q000201:enzymology* / Q000235:genetics; D003300:Copper / Q000494:pharmacology; D004260:DNA Repair / Q000187:drug effects / Q000502:physiology; D043382:DNA-Formamidopyrimidine Glycosylase / Q000096:biosynthesis* / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000502:physiology; D046913:Medicago truncatula / Q000201:enzymology* / Q000235:genetics; D008928:Mitochondria / Q000201:enzymology / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D019913:Nuclear Localization Signals / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D018517:Plant Roots / Q000201:enzymology* / Q000235:genetics; D011092:Polyethylene Glycols / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D018749:RNA, Plant / Q000096:biosynthesis / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000201:enzymology* / Q000235:genetics; D013501:Surface-Active Agents / Q000494:pharmacology; D014131:Trace Elements / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D024101:Mitochondrial Proteins; D019913:Nuclear Localization Signals; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D017382:Reactive Oxygen Species; D013501:Surface-Active Agents; D014131:Trace Elements; D011092:Polyethylene Glycols; D003300:Copper; D043382:DNA-Formamidopyrimidine Glycosylase