title: Oxidative post translational modifications of proteins related to cell cycle are involved in cadmium toxicity in wheat seedlings.
abstract: Abiotic stress is greatly associated with plant growth inhibition and redox cell imbalance. In the present work, we have investigated in which way oxidative posttranslational modifications (PTM) of proteins related to cell cycle may be implicated in post-germinative root growth reduction caused by cadmium, by methyl viologen (MV) and by hydrogen peroxide (H₂O₂) in wheat seedlings. Although cadmium is considered a redox inactive metal, reactive oxygen species were detected in the apex root of metal-treated seedlings. Oxidative stress hastened cells displacement from the cell division zone to elongation/differentiation zone, resulting in a shortened meristem. The number of cells in the proliferation zone was lower after MV, H₂O₂ and 10 μM Cd²⁺ treatments compared to control. All treatments increased protein carbonylation. Although no modification in total Ub-conjugated proteins was detected, oxidative treatments reduced cyclin D and CDKA protein ubiquitination, concomitantly with a decrease in expression of cyclin D/CDKA/Rb/E2F-regulated genes. We postulate that ROS and oxidative PTM could be part of a general mechanism, specifically affecting G1/S transition and progression through S phase. This would rapidly block cell cycle progression and would allow the cellular defence system to be activated.
authors.affiliation: Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, Buenos Aires-C1113AAC, Argentina.
authors.forename: Liliana B
authors.initials: LB
authors.lastname: Pena
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Barcia
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Azpilicueta
authors.forename: Andrea A E
authors.initials: AA
authors.lastname: Méndez
authors.forename: Susana M
authors.initials: SM
authors.lastname: Gallego
mesh_terms: D000199:Actins / Q000235:genetics; D015153:Blotting, Western; D002104:Cadmium / Q000633:toxicity*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D056741:Cyclin D / Q000378:metabolism; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000633:toxicity; D018519:Meristem / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D016877:Oxidants / Q000633:toxicity; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010269:Paraquat / Q000633:toxicity; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D054875:Ubiquitination / Q000187:drug effects
chemical_list: D000199:Actins; D018797:Cell Cycle Proteins; D056741:Cyclin D; D016877:Oxidants; D010940:Plant Proteins; D018809:Proliferating Cell Nuclear Antigen; D017382:Reactive Oxygen Species; D002104:Cadmium; D006861:Hydrogen Peroxide; D018844:Cyclin-Dependent Kinases; D010269:Paraquat