Spd浸种对Cd胁迫下油菜幼苗的抗氧化系统的影响

Effects of Spermidine(Spd) Soaking on Seedling Antioxidant System of Brassica napus Linn.Under Cd Stress

采用水培试验,研究了0.20mmol·L-1Cd2+浓度下,0.10mmol·L-1亚精胺(Spd)浸种处理对油菜幼苗叶片抗氧化系统的影响。结果表明,Cd胁迫使油菜幼苗叶片褪绿,叶绿素总量及叶绿素a/b含量与对照相比极显著降低,Spd浸种处理可显著逆转这一变化,缓解叶片的褪绿现象。与Cd处理相比,Spd浸种显著或极显著提高了油菜幼苗中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性和可溶性蛋白、谷胱甘肽(GSH)含量,从而降低了丙二醛(MDA)含量,极显著降低了超氧阴离子(O-2·)含量,缓解了Cd的氧化胁迫作用。总之,Spd浸种处理通过提高Cd胁迫下植株体内抗氧化酶及抗氧化剂活性,降低活性氧(ROS)水平来缓解重金属胁迫对油菜幼苗的伤害,提高幼苗的耐重金属能力。

A hydroponic experiment was conducted to study the effect of exogenous Spermidine（Spd）（0.01 mmol·L-1） presoaking on seedling（Brassica napus Linn） antioxidative system under 0.20 mmol·L-1 Cd2＋ stress.The results showed Cd stress caused the declining of total chlorophyll,chlorophyll a/b content and seedling chlorosis.However,Spd presoaking seed could significantly relieve these symptoms including seedling chlorosis.Spd soaking seed significantly improved the activaties of superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） and increased the content of soluble protein and glutathione in seedling.Consequently,the content of malondialdehyde（MDA） and superoxide anion（O-2·） decreased and Cd stress was relieved.In short,Spd soaking treatment alleviated Cd harm and improved Cd resistance through increasing the activities of antioxidant enzymes as well as antioxidants and reducing the activity of reactive oxygen species（ROS） in seedling.