镉胁迫对洋常春藤生长及生理特性的影响

Effects of Different Cadmium Stress on Growth and Physiological Characteristics of Hedera helix

  • 摘要: 以当年生洋常春藤扦插苗为研究对象,用CdCl2溶液对其进行镉胁迫处理,研究不同浓度镉胁迫对其生长形态和抗氧化酶系统的影响。结果表明:在20 μmol/L和80 μmol/L镉胁迫处理下,洋常春藤生长及生物量累积受影响较小,其根系和节间出现不明显的伸长,超氧阴离子、丙二醛含量差异不显著,但在80 μmol/L镉胁迫下,过氧化氢酶和过氧化物酶活性比对照分别升高5和6倍。在400 μmol/L镉胁迫下,其株高、节间长、叶片数以及叶生物量与对照相比均显著降低,而超氧阴离子和丙二醛的含量分别比对照增加72.3%和56.2%;可溶性蛋白、脯氨酸含量、抗坏血酸过氧化酶和过氧化物酶活性均显著增加,分别比对照高了约2倍、6倍、2倍和14.7倍,说明此时渗透调节物质的累积及抗氧化酶活性的提高不足以缓解高镉胁迫造成的过氧化伤害。可见,洋常春藤可通过调节部分渗透物质如可溶性蛋白、脯氨酸含量,以及调控抗氧化酶系统中的过氧化氢酶和过氧化物酶活性等来抵抗较低浓度的镉胁迫。

     

    Abstract: Taking Hedera helix cutting seedlings of the year as the research object, the CdCl2 solution was used for stress treatment. The effects of different concentrations of cadmium stress on growth morphology and antioxidant enzyme system were studied. Results show that under Cd2+ stress treatment of 20 μmol/L and 80 μmol/L, the growth and biomass accumulation of H. helix are less affected. there is no significant elongation of shoots and internode of H. helix. and the difference in superoxide anion and malondialdehyde content was not significant. However, catalase and peroxidase activities are 5 and 6 times higher than the control under 80 μmol/L Cd2+ stress, respectively. Under the stress of 400 μmol/L Cd2+, the plant height, internode length, leaf number and leaf biomass are significantly lower than the control, while the content of superoxide anion and malondialdehyde increased by 72.3% and 56.2%, respectively. Soluble protein, proline content, ascorbate peroxidase and peroxidase activities increase significantly, about 2 times, 6 times, 2 times and 14.7 times higher than the control, respectively. It indicates that the accumulation of osmotic adjustment substances and the increase of antioxidant enzyme activity at this time are not enough to alleviate the peroxidation damage caused by high Cd2+ stress. It can be seen that H. helix can resist lower concentrations of Cd2+ stress by regulating partial osmotic substances such as soluble protein, proline content, and regulating catalase and peroxidase activities in antioxidant enzyme systems.

     

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