氧化胁迫对沉水植物黑藻抗冷力的影响

以3种不同质量浓度的H2O2分别对沉水植物黑藻做3种不同程度的氧化胁迫预处理,再经冷胁迫后测定黑藻顶枝的膜脂过氧化程度(MDA含量)、细胞抗氧化酶(SOD,CAT)活性.结果发现低浓度氧化胁迫预处理(0.06mmol/L的H2O2浸泡4或6 h预处理组)的黑藻经冷胁迫处理后,成活率不降低,其膜脂过氧化程度和细胞抗氧化酶的活性还有提高;而经中、高浓度氧化胁迫预处理(0.60mmol/L的H2O2浸泡6和12 h预处理组或1.00mmol/L的H2O2浸泡4,6和12 h预处理组)后的黑藻在冷胁迫处理后的结果则相反.因此,沉水植物黑藻对氧化胁迫感知并做出反应的机制(氧化应激机制),在其对低温反应和适应过程中起着很重要的调节作用.建议早春时节在进行水生植物恢复过程中可采用适宜浓度的H2O2预处理植株,以提高植株的适应性和保持成活率,进一步提高水生植物恢复的效率和效果.

Effect of Oxidative Stress on Cold Tolerance in Hydrilla verticillata

Three dosages of H_2O_2 were respectively used for oxidative stress pretreatment for sink water plant Hydrilla verticillata and processed with cold tolerance,to measure the membrane-lipid peroxidation degree(malondialdehyde(MDA)content) of height shoot of Hydrilla verticillata and the activities of cell antioxidases(superoxide dismutase(SOD) and catalase(CAT)).The results showed that mild oxidative stress((0.06 mmol/L H_2O_2 pretreated for 4 or 6 h) could keep Hydrilla verticillata not to decrease and increase membrane-lipid peroxidation and cell antioxidases activity.If pretreated with high oxidative stress(0.60 mmol/L H_2O_2 pretreated for 6,12 h or 1.00 mmol/L H_2O_2 pretreated for 4,6 and 12 h),the situation is opposite.This means that the mechanism of Hydrilla verticillata responding to oxidative stress might play important regulatory role for Hydrilla verticillata during chilling stress.It was suggested that during lake restoration in early spring,macrophytes could be pretreated with suitable dosage of H_2O_2 to improve their survival rate and adaptability and to further enhance the efficiency and effectiveness of macrophytes.