根际低氧对不同抗性牡丹植株AsA-GSH循环代谢的影响

Effect of Root Zone Hypoxia Stress on AsA-GSH Between Two Peony Varieties

以牡丹品种"洛阳红""胡红"为试材,研究了2种牡丹根际低氧胁迫下AsA-GSH循环代谢应答机制。结果表明:2种牡丹叶、根内H2O2、GSSG含量显著增加;总AsA、AsA、DHA、AsA/DHA、GSH、总GSH、GSH/GSSG、APX、GR含量先增加后降低。峰值时"洛阳红"叶、根内AsA/DHA分别增加42.7%、15.6%;"胡红"叶、根内AsA/DHA分别增加24.3%、35.6%。第3天"洛阳红"叶、根内GSH/GSSG达最大值,分别比对照增加29.1%、9.8%。第2天"胡红"叶、根内GSH/GSSG达最大值,分别比对照增加42.3%、42.7%。表明低氧胁迫下"洛阳红"具有完善的AsA-GSH循环代谢调节机制和较好的H2O2清除能力,比"胡红"更耐根际低氧。

The objectives of this research were to study the effect of hypoxia stress on AsA-GSH system and the mechanism of how free radicals to be scavenged between two different resistance of Paeonia suffruticosa under hypoxia stress.Two 3-year-old strong,uniform peony varieties seedling（P.suffruticosacv.‘Luoyanghong＇and P.suffruticosa cv.‘Huhong＇,the former was quite resistant,while the latter was much sensitive to hypoxia according to the preparatory experiments.）were selected and planted in hydroponics.Nutrient solutions were aerated with nitrogen to induce hypoxia stress conditions.Activities of reactive oxygen species（ROS）-scavenging enzymes including ascorbate peroxidase（APX）,glutathione reductase（GR）,contents of antioxidants such as ascorbic acid（AsA）,glutathione（GSH）,ratio of total AsA to oxidative ascorbic acid（AsA/DHA）,ratio of GSH to oxidative glutathione（GSH/GSSG）were investigated as well as the contents of H_2O_2 of leaves and roots.The results showed that,under hypoxia stress,activities of AsA,AsA,DHA,AsA/DHA,GSH,total GSH,GSH/GSSG,APX,GR were all stimulated and increased greatly in leaves and roots.The growth rate and activity peaks of AsA-GSH anti-active oxygen enzymes in leaves and roots of‘Luoyanghong＇were higher than those of‘Huhong＇.The contents of H2O2 in leaves and roots under hypoxia stress increased significantly.However,the increase ratio and peak contents of H2O2 in leaves and roots of‘Luoyanghong＇were much lower than those of‘Huhong＇.In conclusion,‘Luoyanghong＇held higher tolerance to root-zone hypoxia stress than‘Huhong＇.