重金属胁迫下四种红树植物幼苗生理响应特征

Physiological response characteristics of four mangrove plants seedlings to heavy metal stress

研究了四种红树植物红海榄、秋茄、木榄、角果木幼苗在不同浓度重金属水溶液胁迫28天后的生理生化指标变化特征,包括可溶性蛋白含量、超氧化物歧化酶(superoxide dismutase, SOD)、过氧化物酶(peroxidase, POD)活性和氧化损伤标志物丙二醛(malondialdehyde, MDA)含量。研究结果表明四种植物叶片内的SOD、POD活性均呈现出先升高后下降趋势,10倍重金属水溶液中的红海榄,5倍重金属水溶液中的秋茄和木榄,以及1倍重金属水溶液中的角果木具有较好的抗氧化酶活性,能有效清除活性氧,减小氧化损伤。在同等浓度重金属水溶液处理下,MDA含量结果显示红海榄受损程度最轻,秋茄、木榄受损程度居中,角果木受损程度最重。红海榄抗重金属胁迫能力强于秋茄、木榄,角果木抗重金属能力最弱。上述四种红树植物对重金属的抗性结果说明红树科植物具有较强的抗污染能力,这对于我国红树林生态修复与保护具有重要的指导意义。

The change characteristics of physio-biochemical indexes of four mangrove plants Rhizophora stylosa, Kandelia obovata, Bruguiera gymnorhiza and Ceriops tagal seedlings after 28 days of heavy metal aqueous solution stress at different concentrations were studied, including soluble protein content, superoxide dismutase(SOD), and peroxidase(POD) activity and oxidative damage marker malondialdehyde(MDA) content. The study results showed that the SOD and POD activities in the leaves of the four plants all increased first and then decreased. When the Rhizophora stylosa were treated with 10 times the heavy metal aqueous solution, the Kandelia obovata and Bruguiera gymnorhiza were treated with 5 times the heavy metal aqueous solution, the Ceriops tagal were treated with 1 time the heavy metal aqueous solution, it has good antioxidant enzyme activity during heavy metal aqueous solution treatment, which can effectively remove active oxygen and reduce oxidative damage. Under the same concentration of heavy metal aqueous solution treatment, the results of MDA content showed that the damage of the Rhizophora stylosa was the least, the Kandelia obovata and the Bruguiera gymnorhiza were equally damaged,and the Ceriops tagal were the heaviest. The ability of Rhizophora stylosa to resist heavy metal stress is stronger than Kandelia obovate and Bruguiera gymnorhiza, while the ability of Ceriops tagal to resist heavy metal is the weakest. These results show that mangrove plants have strong ability for anti-pollution, which has important guiding significance for mangrove ecological restoration and protection in China.