紫苏对不同浓度镉胁迫的生理响应

Physiological response of Perilla frutescens (L.) Britt. to cadimium

  • 摘要: 为探讨紫苏的耐镉生理机制, 通过水培试验, 研究了镉离子浓度为0 mg·L-1(对照)、2.0 mg·L-1、5.0 mg·L-1、10.0 mg·L-1 条件下紫苏的生长、镉富集作用及叶片的保护酶活性。结果表明, 2.0 mg·L-1、5.0 mg·L-1、10.0 mg·L-1 镉胁迫下, 紫苏单株生物量比对照分别减少28.4%、42.4%、66.0%, 不同处理间均存在极显著差异;3 个镉离浓度下紫苏的镉富集量依次为462.4 μg·株-1、705.0 μg·株-1、609.7 μg·株-1, 富集系数依次为91.9、70.0、51.1, 具备镉超积累能力。此外, SOD、POD、CAT 酶活测定结果显示, 随镉离子浓度升高, 紫苏叶片的SOD 活性和MDA 含量显著升高, POD 和CAT 活性显著下降, 破坏了体内保护酶系统的平衡, 抑制紫苏生长。

     

    Abstract: Hydroponic culture experiments were conducted to study physiological characteristics of Perilla frutescens (L.) Britt. under cadmium stress. The paper analyzed P. frutescens growth, cadmium accumulation and protective enzyme activities in leaf at Cd2+ concentrations of 0 mg·L-1, 2.0 mg·L-1, 5.0 mg·L-1 and 10.0 mg·L-1, respectively. The study showed that the per plant biomass of P. frutescens under cadmium stress dropped by 28.4%, 42.4% and 66.0% compared with control (0 mg·L-1 Cd2+), respectively. Extremely significant differences were noted among the different treatments. Per plant cadmium accumulation capacities under the cadmium treatments were 462.4 μg, 705.0 μg and 609.7 μg, with enrichment coefficients of 91.9, 70.0 and 51.1, respectively. This showed the superior ability of P. frutescens to accumulate cadmium or resist cadmium stress. Tests for SOD, POD and CAT enzyme activities further showed significant increases in SOD activity and MDA content in P. frutescens leaves under cadmium treatments. On the other hand, POD and CAT activities significantly dropped with increasing cadmium concentration. High cadmium concentration destructed protective enzyme balance, which restrained growth of P. frutescens.

     

/

返回文章
返回