摘要
放牧对草地植物的直接影响包括动物的采食和践踏。为了探讨冷蒿Artemisia frigida的耐牧性,采用人工机械损伤(轻度、中度和重度)的方式处理盆栽冷蒿地上枝叶,分别测定冷蒿叶片和根系活性氧(ROS),丙二醛(MDA),抗坏血酸(AsA)和谷胱甘肽(GSH)质量摩尔浓度,同时测定了抗氧化防御酶和抗坏血酸(AsA)-谷胱甘肽(GSH)循环酶活性的变化。结果表明:随着机械损伤强度的增加,冷蒿叶片超氧阴离子(O_2·-)和过氧化氢(H_2O_2)质量摩尔浓度升高,膜质过氧化增强;超氧化物歧化酶(SOD),过氧化氢酶(CAT)和过氧化物酶(POD)活性随机械损伤强度的增加而升高。在轻度和中度处理下,冷蒿叶片中抗坏血酸过氧化物酶(APX),脱氢抗坏血酸还原酶(DHAR),单脱径抗坏血酸还原并(MDHAR)和谷胱甘肽还原酶(GR)活性增强,抗氧化剂(AsA和GSH)的还原力(ρ_(AsA)/ρ_(DHA)值和ρ_(GSH)/ρ_(GSSG)值)处于稳定平衡状态;重度机械损伤下AsA-GSH循环效率显著降低(P≤0.05)。冷蒿根系抗氧化防御系统对机械损伤也表现出明显的应激反应能力。综上所述,机械损伤使冷蒿体内ROS质量摩尔浓度升高,且冷蒿能够在不同程度的机械损伤下快速、有效地启动体内抗氧化防御系统,清除体内过量的ROS,维持一定的AsA-GSH循环效率,表现出较强的耐损伤能力。
To understand the effects of mechanical damage on the antioxidant defense system of A rtemisiafrigi- da, we analyzed the changes of reactive oxygen species （ROS） level, antioxidant enzyme activities, and ascorroate-glutathione （AsA-GSH） cycle efficiency under light, moderate, and heavy mechanical damage. Results showed that with a mechanical damage treatment, the O＇2-production rate, H202, and malondialdehyde （MDA） contentincreased significantly （P≤0.05） in leaves and roots of A. frigida and was significantly lower （P≤ 0.05） in roots than in leaves. Also, activities of superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） were significantly higher （P≤0.05） with the mechanical damage treatment compared to the control. The activities of ascorbate peroxidase （APX）, monodehydroascorbate reductase （MDHAR）, dehydroascorbate reductase （DHAR）, and glutathione reductase （GR）, as well as regenerating rates of AsA and GSH, and redox statuses （ratios of AsA/DHA and GSH/GSSG） with light and moderate mechanical damage were not significantly different （P≥0.05） from the control; whereas compared to the control efficiency of the AsA-GSH cycle was significantly lower （P≤ 0.05） with heavy mechanical damage. The antioxidant defense system in roots of A. frigida also showed obvious stress in response to mechanical damage capacities. It was concluded that with light and moderate mechanical damage A. frigida had an efficient metabolism in the ascorbate-glutathione cycle, which rapidly scavenged H202 to alleviate the oxidative damage and, therefore, had a stronger tolerance to me- chanical stress damage. [ Ch, 4 fig. 1 tab. 42 ref.]
出处
《浙江农林大学学报》
CAS
CSCD
北大核心
2016年第3期462-470,共9页
Journal of Zhejiang A&F University
基金
国家自然科学基金资助项目(31270756
31470704)
国家重点基础研究发展计划("973"计划)项目(2014CB138805)
"十二五"国家科技支撑计划项目(2011BAC07B01)
