褪黑素通过减少镉吸收和增加抗氧化物能力提高生菜镉耐性

摘要：水培条件下，以生菜为实验材料，研究合适浓度的褪黑素对缓解生菜镉胁迫的影响。我们分别研究了不同处理条件下生菜幼苗的生理指标。结果表明，在 50 μM 褪黑素与镉同时处理生菜幼苗时，幼苗的根长、地上部干鲜重、和地下部的干鲜重比单独镉处理组均有显著提高。单独镉胁迫的生菜幼苗中，丙二醛（MDA）、 H2O2 含量上升，超氧化物歧化酶（SOD）活性上升，过氧化氢酶（CAT），抗坏血酸过氧化物酶（APX）活性降低；镉胁迫下加入浓度为 50 μM 的褪黑素，丙二醛（MDA）、H2O2 含量有所下降，超氧化物歧化酶（SOD），过氧化氢酶（CAT），过氧化物酶（POD），抗坏血酸过氧化物酶（APX）活性显著升高，且植株镉含量显著下降。 25792
毕业论文关键词：镉胁迫，褪黑素，生菜幼苗，抗氧化物
Melatonin enhances cadmium tolerance in lettuceby reducing cadmium uptake and increasing antioxidantcapacities Abstract：The effect of melatonin on the cadmium stress of lettuce was studied by using lettuce as experimental material with solution culture. We studied the physiological indexes of lettuce seedlings under different treatment conditions. The results showed that the root length, shoot and underground fresh weight and dry weight of the seedlings, which were compared with ones treated with cadmium only, were significantly increased when lettuce seedlings were treated with 50 mmol / L melatonin and cadmium at the same time. The contents of malondialdehyde (MDA) and H2O2 were increased, the activity of superoxide dismutase (SOD) was increased, and the activity of catalase (CAT) and ascorbate peroxidase (APX) was decreased in cadmium stress. The contents of malondialdehyde (MDA) and H2O2 of lettuce seedlings treated with cadmium and 50 mmol / L melatonin were decreased, and the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) were significantly increased, and plant cadmium content decreased significantly.
Key words：Cadmium stress，Melatonin，lettuce，antioxidant

目录
摘要 3
关键词 3
Abstract . 3
Key word 3
1材料与方法 . 4
1.1实验材料 4
1.1.1材料培养 . 4
1.1.2材料处理 . 4
1.2测定方法 4
1.2.1生菜生长指标的测定 4
1.2.2叶绿素含量的测定 4
1.2.3可溶性蛋白含量测定（考马斯亮蓝染色法） 4
1.2.4超氧化物歧化酶（SOD）活性测定（氮蓝四唑光化还原法） 5
1.2.5过氧化物酶（POD）活性测定（愈创木酚法） 5
1.2.6过氧化氢酶（CAT）活性测定 5
1.2.7抗坏血酸过氧化物酶（APX）活性的测定 5
1.2.8丙二醛（MDA）含量测定 5
1.2.9 H2O2含量的测定 5
1.2.10镉含量的测定 5
1.3 数据分析与处理方法 6
2 结果与分析 6
2.1褪黑素对生菜幼苗生长的影响 . 6
2.2褪黑素对生菜幼苗中叶绿素含量的影响 . 6
2.3褪黑素对生菜幼苗中可溶性蛋白含量的影响 . 7
2.4褪黑素对生菜幼苗中 SOD活性的影响 . 7
2.5褪黑素对生菜幼苗中 POD活性的影响 . 8
2.6褪黑素对生菜幼苗中 CAT活性的影响 . 8
2.7褪黑素对生菜幼苗中 APX活性的影响 . 9
2.8褪黑素对生菜幼苗中丙二醛（MDA）含量的影响 9
2.9褪黑素对生菜幼苗中 H2O2 含量的影响 . 10
2.10 褪黑素对生菜幼苗中 Cd含量的影响 . 10
3 讨论 .11
3.1褪黑素能够缓解镉胁迫造成的膜脂过氧化伤害 11
3.2褪黑素能够缓解镉胁迫造成的生物量降低 11
3.3褪黑素对各种抗氧化酶的影响 11
致谢 12
参考文献 12 褪黑素通过减少镉吸收和增加抗氧化物能力提高生菜镉耐性:http://www.youerw.com/shengwu/lunwen_19706.html