Nitric oxide protects sunflower leaves against cadmium-induced oxidative stress

LASPINA NV; GROPPA MD; TOMARO ML; BENAVIDES MP

PLANT SCIENCE

Elsevier Science

Lugar: Holanda; Año: 2005 vol. 167 p. 323 - 330

0168-9452

Nitric oxide is a bioactive molecule involved in many biological events that has been reported as prooxidant as well as antioxidant inplants. In the present study, we evaluated the protective effect of nitric oxide (NO) against Cd-induced oxidative stress in sunflower leaves.Leaves from seedlings pretreated before metal exposure with 100 m M sodium nitroprusside (SNP) as NO donor significantly reversed dryweight loss and chlorophyll decay induced by the metal. The raise on lipid peroxidation and the 30% decrease in GSH content observed in Cd-treatedleaves was reverted by NO treatment. Ascorbate (ASC) content increased greatly under Cd stress, but this increase was reversed bySNP pretreatment. NO prevented Cd-induced increase in the activity of superoxide dismutase (SOD) and restored catalase (CAT) activity,which was 44% reduced in Cd-treated plants. Glutathione reductase (GR) and peroxidase (GPOX) were scarcely affected by the metal, andNO did not produced any remarkable effect on their activities. All together, these results suggest that the exogenous application of NO couldbe advantageous against Cd toxicity, and could confer tolerance to heavy metal stress in plants.