铝·铅及其互作胁迫对大麦幼苗生长和抗逆生理代谢的影响

摘要

[目的]为明确铝(Al)、铅(Pb)及其交互作用对大麦幼苗生长及抗氧化代谢的影响.[方法]采用营养液培养方法,研究了胁迫处理10 d后不同浓度Al、Pb单独及复合胁迫对大麦幼苗株高、根长等生长指标和功能叶超氧化物歧化酶(SOD)、过氧化物酶(POD)的活性以及丙二醛(MDA)、游离脯氨酸含量的影响.[结果]单一Al、Pb胁迫处理均在0.05水平显著抑制大麦幼苗生长,表现为根长、株高等生长指标均在0.05水平显著低于对照.胁迫处理导致大麦叶片中SOD、POD活性及MDA、游离脯氨酸含量上升,且A1处理下随着胁迫浓度增加的幅度加大.Al、Pb复合处理时,大麦幼苗生长受抑制程度及SOD、POD活性和MDA、游离脯氨酸含量高于相应单一Al处理值.植株生长、SOD、POD活性及MDA含量以200 μmol/L Al+150μmol/L Pb处理下变幅最大,但游离脯氨酸含量在50 μmol/LAl+150 μmol/L Pb复合处理时最高.[结论]Al、Pb复合处理引发更严重的生长抑制和氧化胁迫.%[Objective] The research aimed to clarify the effects of aluminum and lead single and combinational stresses on the growth and physiological metabolisms of barley seedlings.[Method] Hydroponic experiment was conducted to investigate the effects of aluminum and lead single and combinational stress on plant height,root length,the activities of peroxidase (POD) and superoxide dismutase (SOD),as well as the contents of malondialdehyde (MDA) and free proline in barley leaves after 10 d stress exposure.[Result] Al or Pb stresses adversely affected plant growth expressed by root length and shoot height,markedly increased the activities of POD and SOD,as well as the contents of MDA and free proline.The change range of all these indexes increased with the increase of Al concentration in solution.Binary metal stress caused more serious growth inhibition and metabolisms disorder.The increases of the activities of POD and SOD,MDA contents were detected under the stress of 200 μmol/L Al + 150 μmol/L Pb,while the most significant increase in free proline content was observed under the stress of 50 μmol/L Al + 150 μmol/L Pb.[Conclusion] Combination of aluminum and lead could cause serious growth inhibition and oxidative stress.