School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
Ecotoxicol Environ Saf. 2011 Jul;74(5):1310-5. doi: 10.1016/j.ecoenv.2011.02.006. Epub 2011 Mar 3.
The effects of 100 μM Pb(NO₃)₂ on 7-day-old Arabidopsis thaliana seedlings grown from seeds pretreated with a nitric oxide donor, sodium nitroprusside (SNP), or a nitric oxide scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) were investigated. Physiological stress induced by Pb (reduced root growth) was less evident in seedlings grown from seeds pretreated with SNP. However, SNP pretreatment of seeds did not affect Pb accumulation in the seedlings. Pb exposure caused oxidative stress by elevating hydrogen peroxide (H₂O₂) and lipid hydroperoxide contents of the seedlings. SNP pretreatment of seeds counteracted Pb toxicity by reducing the H₂O₂ and lipid hydroperoxide contents of Pb-exposed seedlings. Additionally, Pb-induced rises in antioxidative enzyme activities were reversed by SNP pretreatment of seeds. It was concluded that the ameliorating effects of SNP pretreatment were associated with the release of nitric oxide because cPTIO reversed these effects of SNP pretreatment of seeds and more importantly SNP pretreatment did not trigger an avoidance mechanism.
研究了用一氧化氮供体硝普钠（SNP）或一氧化氮清除剂 2-（4-羧基苯基）-4,4,5,5-四甲基咪唑啉-1-氧-3-氧化物（cPTIO）预处理种子对生长 7 天的拟南芥幼苗暴露于 100 μM Pb(NO₃)₂的影响。与 SNP 预处理的种子生长的幼苗相比，Pb 诱导的生理胁迫（根生长减少）在 SNP 预处理的种子生长的幼苗中不太明显。然而，SNP 预处理种子并不影响幼苗中 Pb 的积累。Pb 暴露通过提高幼苗中过氧化氢（H₂O₂）和脂质过氧化物的含量引起氧化应激。SNP 预处理种子通过降低 Pb 暴露幼苗中 H₂O₂和脂质过氧化物的含量来拮抗 Pb 毒性。此外，Pb 诱导的抗氧化酶活性的升高被 SNP 预处理种子逆转。结论是 SNP 预处理的改善作用与一氧化氮的释放有关，因为 cPTIO 逆转了 SNP 预处理种子的这些作用，更重要的是，SNP 预处理不会引发回避机制。
