摘要:
通过盆栽实验研究了抗性植物狼尾草根部丙二醛(MDA)、脯氨酸(Pro)、抗坏血酸(AsA)含量及超氧化物歧化酶(SOD)、谷胱甘肽还原酶(GR)等氧化应激生理指标对不同浓度阿特拉津长期(48 d)胁迫的响应规律。结果表明:当阿特拉津胁迫浓度分别高于20 mg·kg-1和50 mg·kg-1时,狼尾草根系的MDA与Pro含量较对照组显著升高(P < 0.05);随着阿特拉津胁迫浓度的增加,狼尾草根部SOD和GR活性呈先升高后降低的趋势,其中当阿特拉津胁迫浓度为20 mg·kg-1时,SOD和GR活性达到最大值;供试植物根系中AsA含量与阿特拉津胁迫浓度呈正相关。综上,中低浓度(≤ 20 mg·kg-1)阿特拉津处理没有对狼尾草的根系产生明显的氧化胁迫效应,狼尾草根系的上述抗氧化应激生理指标对于发挥阿特拉津抗性起着重要的作用。
关键词:
-
阿特拉津
/
-
狼尾草
/
-
根系
/
-
氧化应激
/
-
长期胁迫
Abstract:
Pennisetum americanum L. (cv. K. Schum) has been reported as a phytoremediator which exhibits tolerance to atrazine. Atrazine is a herbicide that can effectively control broadleaf and grass weeds, but its use also causes serious pollution issues. To evaluate the influence of atrazine stress on the tolerant plant, an experiment was conducted focusing on the response of malondialdehyde (MDA), proline (Pro), ascorbic acid (AsA) content, superoxide dismutase (SOD) and glutathione reductase (GR) activities in the root of P. americanum exposed to different concentrations of atrazine during a long-term (48 d) period. The results showed that MDA and Pro contents in the root of the plant increased significantly under atrazine concentrations above 20 mg·kg-1 and 50 mg·kg-1, respectively, when compared with the control (P < 0.05). With the increase in atrazine concentration, SOD and GR activities in the root of P. americanum first increased and then decreased; their activities reached the maximum when exposed to 20 mg·kg-1 atrazine. AsA content in the root of the test plant and atrazine concentration were positively correlated. The above results demonstrated that low atrazine concentrations (≤ 20 mg·kg-1) did not show significant oxidative stress effect on the root of P. americanum. Physiological response characteristics of the antioxidant defense system in the root of the test plant played an important role for atrazine tolerance.
点击查看大图
下载:
