Shi Qinghua, Ding Fei, Wang Xiufeng, Wei Min
State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian 271018, PR China.
Plant Physiol Biochem. 2007 Aug;45(8):542-50. doi: 10.1016/j.plaphy.2007.05.005. Epub 2007 May 27.
Mitochondria are subcellular organelles with an essentially oxidative type of metabolism. The production of reactive oxygen species (ROS) in it increases under stress conditions and causes oxidative damage. In the present study, effects of exogenous sodium nitroprusside (SNP), a nitric oxide (NO) donor, on both the ROS metabolism in mitochondria and functions of plasma membrane (PM) and tonoplast were studied in cucumber seedlings treated with 100mM NaCl. NaCl treatment induced significant accumulation of H(2)O(2) and led to serious lipid peroxidation in cucumber mitochondria, and the application of 50muM SNP stimulated ROS-scavenging enzymes and reduced accumulation of H(2)O(2) in mitochondria of cucumber roots induced by NaCl. As a result, lipid peroxidation of mitochondria decreased. Further investigation showed that application of SNP alleviated the inhibition of H(+)-ATPase and H(+)-PPase in PM and/or tonoplast by NaCl. While application of sodium ferrocyanide (an analog of SNP that does not release NO) did not show the effect of SNP, furthermore, the effects of SNP were reverted by addition of hemoglobin (a NO scavenger).
线粒体是具有基本氧化代谢类型的亚细胞细胞器。在应激条件下，其活性氧（ROS）的产生会增加并导致氧化损伤。在本研究中，对用100mM NaCl处理的黄瓜幼苗，研究了一氧化氮（NO）供体外源硝普钠（SNP）对线粒体中ROS代谢以及质膜（PM）和液泡膜功能的影响。NaCl处理诱导黄瓜线粒体中H₂O₂大量积累并导致严重的脂质过氧化，而施加50μM SNP可刺激ROS清除酶并减少NaCl诱导的黄瓜根线粒体中H₂O₂的积累。结果，线粒体的脂质过氧化减少。进一步研究表明，施加SNP可减轻NaCl对PM和/或液泡膜中H⁺-ATP酶和H⁺-PP酶的抑制作用。而施加亚铁氰化钠（一种不释放NO的SNP类似物）未显示出SNP的效果，此外，添加血红蛋白（一种NO清除剂）可逆转SNP的作用。
