Priming with NO controls redox state and prevents cadmium-induced general up-regulation of methionine sulfoxide reductase gene family in Arabidopsis

• Published in: Biochimie Vol. 131; pp. 128 - 136
• Main Authors: Méndez, Andrea A.E., Pena, Liliana B., Benavides, María P., Gallego, Susana M.
• Format: Journal Article
• Language: English
• Published: France Elsevier B.V 01-12-2016
• Subjects: Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Cadmium; Cadmium - toxicity; Chlorophyll - metabolism; Chloroplasts - drug effects; Chloroplasts - metabolism; Electrophoresis, Polyacrylamide Gel; Gene Expression Regulation, Plant - drug effects; Methionine Sulfoxide Reductases - genetics; Methionine Sulfoxide Reductases - metabolism; Microscopy, Fluorescence; MSR; Multigene Family; Nitric Oxide - metabolism; Nitric Oxide Donors - metabolism; Nitric Oxide Donors - pharmacology; Nitroprusside - metabolism; Nitroprusside - pharmacology; Oxidation-Reduction - drug effects; Oxidative stress; Peroxidase - metabolism; Plant Leaves - drug effects; Plant Leaves - genetics; Plant Leaves - metabolism; Protein Carbonylation - drug effects; Reactive Oxygen Species - metabolism; Redox balance; Reverse Transcriptase Polymerase Chain Reaction; Up-Regulation - drug effects; Redox balance; Oxidative stress; Cadmium; MSR
• ISSN: 0300-9084; 1638-6183
• DOI: 10.1016/j.biochi.2016.09.021

In the present study we evaluated the pre-treatment (priming) of Arabidopsis thaliana plants with sodium nitroprusside (SNP), a NO-donor, as an interesting approach for improving plant tolerance to cadmium stress. We focused on the cell redox balance and on the methionine sulfoxide reductases (MSR) family as a key component of such response. MSR catalyse the reversible oxidation of MetSO residues back to Met. Five MSRA genes and nine MSRB genes have been identified in A. thaliana, coding for proteins with different subcellular locations. After treating 20 days-old A. thaliana (Col 0) plants with 100 μM CdCl2, increased protein carbonylation in leaf tissue, lower chlorophyll content and higher levels of reactive oxygen species (ROS) in chloroplasts were detected, together with increased accumulation of all MSR transcripts evaluated. Further analysis showed reduction in guaiacol peroxidase activity (GPX) and increased catalase (CAT) activity, with no effect on ascorbate peroxidase (APX) activity. Pre-exposition of plants to 100 μM SNP before cadmium treatment restored redox balance; this seems to be linked to a better performance of antioxidant defenses. Our results indicate that NO priming may be acting as a modulator of plant antioxidant system by interfering in oxidative responses and by preventing up-regulation of MSR genes caused by metal exposure.
•NO priming maintain redox balance during Cd stress.•Cd induces general up-regulation of the MSR system.•NO indirectly moderates MSR response during Cd stress through an antioxidant mechanism.