三峡库区消落带野生狗牙根在深水淹结束后根系酶活力动态

Dynamics of Antioxidant Enzyme Activities in Roots of Cynodon dactylon Plants from Hydro-Fluctuation Belt in Three Gorges Reservoir Area after Deep Submergence

本文通过三峡库区自然消落带野生狗牙根实际水淹和非水淹对照对比实验,分析了三峡库区消落带野生狗牙根在水淹结束后参与抗氧化胁迫的关键酶酶活性动态变化。实验结果表明:长期水淹生境下自然消落带野生狗牙根根系过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)酶活性均低于非水淹对照组,其中CAT酶活性显著低于对照组(P<0.01);过氧化物酶(POD)和超氧化物歧化酶(SOD)以及乙醇脱氢酶(ADH)酶活性均显著高于对照组(P<0.01)。恢复期狗牙根根系的POD和SOD酶活性均呈先降后升再降的动态变化趋势,而CAT和GR酶活性均呈先升后将再升的动态变化趋势;至恢复期的第25天4种抗氧化酶酶活性均回复至对照组水平,ADH酶活性在恢复期第5天迅速恢复至对照组水平。恢复期间CAT与GR酶活性,POD与SOD酶活性均表现出显著相关性(P<0.01)。水淹胁迫影响三峡库区自然消落带野生狗牙根根系酶活性,水淹结束后,狗牙根恢复性生长期间根系酶变化与复氧环境下抗氧化胁迫有关。

The actual flooding and control experiments of wild Cynodon dactlonwere were conducted in hydro-fluctuation belt of the Three Gorges Reservoir,and the dynamic activity of antioxidant enzymes was analyzed after flooding.The results showed that （i）Under deep submergence,the activity of glutathione reductase （GR） in the treated group was lower than that in control group,and the activity of CAT in treated group was significantly lower than that in control group （P ＜0.01） ; The activities of peroxidase （POD）,superoxide dismutase （SOD） and alcohol dehydrogenase （ADH） in treated group were significantly higher than that in control group （P ＜ 0.01）.（ii） During the whole period of restoration,the activities of POD and SOD in root showed a down-up-down dynamic trend in the treated group,but the activity of GR and CAT in root showed an up-down-up dynamic trend.（iii）The activity of four kinds of antioxidative enzymes recovered to the levd of control on the 25th day of restoration,and the activity of ADH rapidly dropped to the level of control on fifth day after flooding in the treated group.（iv）It showed significant correlations between CAT and GR,between POD and SOD （P＜0.01） in the treated group.Enzyme activities in roots of Cynodon dactylon from hydro-fluctuation belt in the Three Gorges Reservoir Area were influenced by flooding,and their dynamics were related to reoxygenation conditions after flooding.