Singh Harminder P, Kaur Shalinder, Batish Daizy R, Sharma Ved P, Sharma Nidhi, Kohli Ravinder K
Department of Environment and Vocational Studies, Panjab University, Chandigarh, India.
Nitric Oxide. 2009 Jun;20(4):289-97. doi: 10.1016/j.niox.2009.02.004. Epub 2009 Feb 20.
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.
一氧化氮（NO）是一种具有生物活性的气态多功能分子，在包括重金属在内的生物和非生物胁迫的各种生理过程及反应中发挥核心作用并起介导作用。本研究调查了作为硝普钠（SNP）外源施用的NO对水稻砷（As）毒性是否具有任何保护作用。用50微摩尔SNP（一种NO供体）处理显著改善了As诱导的（25或50微摩尔）水稻根和胚芽鞘长度的降低。此外，在补充NO后，以丙二醛（MDA）、超氧离子（O₂⁻）、根氧化能力和H₂O₂含量衡量的As诱导的氧化应激较小。这表明NO具有活性氧（ROS）清除活性。添加NO（仅部分地）逆转了As诱导的抗氧化酶——超氧化物歧化酶、抗坏血酸过氧化物酶、愈创木酚过氧化物酶和过氧化氢酶活性的增加。该研究得出结论，外源NO使水稻对As毒性具有抗性，并对As诱导的胁迫具有改善作用。
