Nitric oxide alleviates arsenic toxicity by reducing oxidative damage in the roots of Oryza sativa (rice).
Nitric oxide (NO) is a bioactive gaseous, multifunctional molecule playing a central role and mediating a variety of physiological processes and responses to biotic and abiotic stresses including heavy metals. The present study investigated whether NO applied exogenously as sodium nitroprusside (SNP) has any protective role against arsenic (As) toxicity in Oryza sativa (rice). Treatment with 50 microM SNP (a NO donor) significantly ameliorated the As-induced (25 or 50 microM) decrease in root and coleoptile length of rice. Further, As-induced oxidative stress measured in terms of malondialdehyde (MDA), superoxide ion (O(2)(-)), root oxidizability and H2O2 content was lesser upon supplementation of NO. It indicated a reactive oxygen species (ROS) scavenging activity of NO. NO addition reversed (only partially) the As-induced increase in activities of antioxidant enzymes - superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, and catalase. The study concludes that exogenous NO provides resistance to rice against As-toxicity and has an ameliorating effect against As-induced stress.
Singh
Harminder P
HP
Department of Environment and Vocational Studies, Panjab University, Chandigarh, India. hpsingh_01@yahoo.com
Kaur
Shalinder
S
Batish
Daizy R
DR
Sharma
Ved P
VP
Sharma
Nidhi
N
Kohli
Ravinder K
RK
D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D001151:Arsenic / Q000633:toxicity*; D019216:Metals, Heavy / Q000633:toxicity; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D012275:Oryza / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D018517:Plant Roots / Q000187:drug effects* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
D000975:Antioxidants; D019216:Metals, Heavy; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D001151:Arsenic