外源茉莉酸甲酯对镉胁迫下高羊茅生长及生理指标的影响

Effects of Exogenous Methyl Jasmonate on Growth and Physiological Indexes of Festuca elata under Cadmium Stress

本研究以镉污染土壤为研究对象,茉莉酸甲酯(MeJA)为缓解剂,将高羊茅作为镉污染土壤的修复草种,通过测定高羊茅的相关生理指标、以及植物和土壤中的镉含量,探究MeJA对高羊茅修复镉污染土壤的影响。结果表明,较单一Cd胁迫(100μmol·L^(-1)),施用MeJA(25~75μmol·L^(-1))可使高羊茅的叶绿素含量、抗氧化酶活性升高,丙二醛(MDA)、游离脯氨酸(Pro)、过氧化氢(H_(2)O_(2))和超氧自由基(·O_(2))含量下降;施用<75μmol·L^(-1)的MeJA可使高羊茅根系和叶片的镉含量最高上升59.58%和38.64%,且土壤的镉含量最多下降27.49%;50μmol·L^(-1)的MeJA浓度下,高羊茅根系鲜重及长度增加了136.79%和58.18%,超过此浓度后,高羊茅代谢被影响,植物体对镉吸附能力减弱。说明一定浓度的MeJA可增强高羊茅的生理活性,从而减轻Cd^(2+)对高羊茅的损害,进一步加强高羊茅对镉污染土壤的修复力。

The impact of heavy metals on the environment has endangered the safety of human survival.How to effectively repair heavy met al damage to the environment has been one of the hot spots.In this study,cadmium-contaminated soil was used as the research object,methyl jasmonate was used as a mitigation agent,and Festuca elata was used as a remediation grass species of cadmium-contaminated soil.The effects of MeJA on the remediation of cadmium-contaminated soil by Festuca elata were explored by measuring the related physiological indexes of Festuca elata,cadmium content in plants and soil.The results showed that compared with single Cd(100μmol·L^(-1))stress,(1)MeJA(25~75μmol·L^(-1))increased the chlorophyll content and antioxidant enzyme activity of Festuca elata,and decreased the contents of malondialdehyde(MDA),free proline(Pro),hydrogen peroxide(H_(2)O_(2))and superoxide radical(·O_(2)^(-)).(2)The application of MeJA at the concentration of<75μmol·L^(-1) increased the cadmium content in roots and leaves of Festuca elataby 59.58%and 38.64%,while the cadmium content in soil decreased by 27.49%.(3)The fresh weight and length of Festuca elata root increased by 136.79%and 58.18%under 50μmol·L^(-1) MeJA concentration.When MeJA exceeded this concentration,the metabolism of Festuca elata was affected,and the adsorption capacity of plants to cadmium was weakened.The results showed that MeJA could enhance the physiological activity of Festuca elata,reduce the damage of Cd^(2+) to Festuca elata,and further strengthen the remediation ability of Festuca elata to cadmium contaminated soil.