Exogenous nitric oxide (as sodium nitroprusside) ameliorates arsenic-induced oxidative stress in watercress (Nasturtium officinale R. Br.) plants

This research investigated the effects of exogenous sodium nitroprusside (SNP) supplementation as a nitric oxide (NO) on alleviating arsenic-induced oxidative damage in watercress (Nasturtium officinale R. Br.) plants. In arsenic-treated plants, dry weight of roots and shoots and chlorophyll content of leaves markedly decreased, while application of 100 mu M SNP, alleviated the inhibitory effect of arsenic on plant growth and chlorophyll content in arsenic-treated plants. Treatment with 100 mu M SNP considerably reduced root-to-shoot translocation of arsenic and increased slightly the protein and praline content in watercress tissues. Level of oxidative markers (lipoxygenase activity and malondialdehyde (MDA) and H2O2 content) sharply increased in arsenic-treated plants. Upon application of SNP this trend was alleviated; however, the activities of enzymatic antioxidants increased when plants were subjected to arsenic stress in combination with SNP. Results obtained in the present study suggest that exogenous NO could alleviate negative effects of arsenic on watercress plants probably through its ability to the stimulation of reactive oxygen species (ROS)-scavenging enzymes activity and/or direct scavenging of superoxide onion. (c) 2013 Elsevier B.V. All rights reserved.