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

MENDEZ AEA; PENA LB; BENAVIDES MP; GALLEGO SM

BIOCHIMIE

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Lugar: Paris; Año: 2016 vol. 131 p. 128 - 136

0300-9084

In the present study we evaluated the pre-treatment (priming) of Arabidopsis thaliana plants with sodiumnitroprusside (SNP), a NO-donor, as an interesting approach for improving plant tolerance tocadmium 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 residuesback to Met. Five MSRA genes and nine MSRB genes have been identified in A. thaliana, coding forproteins with different subcellular locations. After treating 20 days-old A. thaliana (Col 0) plants with100 mM CdCl2, increased protein carbonylation in leaf tissue, lower chlorophyll content and higher levelsof reactive oxygen species (ROS) in chloroplasts were detected, together with increased accumulation ofall 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. Preexpositionof plants to 100 mM SNP before cadmium treatment restored redox balance; this seems tobe linked to a better performance of antioxidant defenses. Our results indicate that NO priming may beacting as a modulator of plant antioxidant system by interfering in oxidative responses and by preventingup-regulation of MSR genes caused by metal exposure