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为探讨姜对镉(Cd)胁迫的生理响应特性,通过外施Cd Cl2·2.5H2O溶液,研究不同Cd水平对姜叶片活性氧代谢的影响。结果表明,Cd胁迫下,姜叶片中生成速率和H2O2含量显著升高,且呈剂量和时间效应,同时丙二醛(MDA)含量和电导率持续增加。姜幼苗期,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)、抗坏血酸过氧化物酶(APX)、单脱氢抗坏血酸还原酶(MDHAR)、脱氢抗坏血酸还原酶(DHAR)、抗坏血酸氧化酶(AAO)等抗氧化酶活性均被Cd胁迫所诱导增强,还原型抗坏血酸(As A)、总抗坏血酸(As A+DHA)、酸溶性SH、还原型谷胱甘肽(GSH)、植物络合素等抗氧化物质含量显著升高,As A/DHA、GSH/GSSG比值显著增加;随Cd胁迫浓度和时间的增加,相关保护酶活性及抗氧化物质含量均显著降低,表明姜对Cd较短期(40 d)胁迫或较低浓度Cd胁迫具有适应性,但胁迫120 d或过高浓度的Cd胁迫严重损伤了姜叶片抗氧化系统,使活性氧代谢失调,叶片膜系统遭到严重伤害。
In order to investigate the physiological response of ginger to cadmium (Cd) stress, the effects of different Cd levels on reactive oxygen metabolism of ginger leaves were studied by applying CdCl 2 2.5H 2 O solution. The results showed that the formation rate and the content of H2O2 in ginger leaves were significantly increased under the Cd stress, and the dose and time were increased. The contents of malondialdehyde (MDA) and conductivity were continuously increased. The contents of SOD, POD, CAT, GR, APX, Ascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and ascorbic acid oxidase (AAO) were all increased by Cd stress. Reduced ascorbic acid (As A + DHA), acid-soluble SH, glutathione (GSH), phytochelin and other antioxidant substances were significantly increased, while the ratios of As A / DHA and GSH / GSSG were significantly increased.With the increase of Cd stress concentration and time , The activities of protective enzymes and the contents of antioxidant substances were significantly decreased, which indicated that ginger was adaptive to Cd stress at a relatively short duration (40 days) or Cd stress at a lower concentration, but Cd stress at 120 days or too high concentration severely damaged ginger Leaf antioxidant system, so that reactive oxygen metabolism disorders, leaf membrane system was severely injured.