水分胁迫条件下CO_2加富对枇杷叶绿素荧光及抗氧化酶的影响

Effects of CO_2 enrichment on chlorophyll fluorescence and antioxidative enzymes in loquat(Eriobotrya japonica Lindl.)under the condition of water-stress

在CO2分别为低浓度(400μmol·mol-1,近似大气的浓度)和高浓度(700μmol·mol-1)下的两个自制开顶式生长室内,研究水分胁迫对2年生大红袍枇杷(EriobotryajaponicaLindl.)叶片的叶绿素荧光及抗氧化酶活性的变化。结果表明,高CO2浓度对枇杷叶片荧光参数Fv/Fm和Fv/Fo值及ΦPSⅡ明显提高;而在水分胁迫条件,高CO2浓度下枇杷叶片荧光参数Fv/Fm和Fv/Fo值及ΦPSⅡ下降幅度明显减少;无水分胁迫时高CO2浓度也使SOD、POD和CAT酶活性显著提高。但在水分胁迫时,高CO2浓度下的SOD、POD和CAT酶活性上升幅度明显较小,膜脂过氧化水平的上升幅度也较小,表明CO2浓度升高对水分胁迫造成的氧化损伤有一定的缓解作用。

Loquat trees(Eriobotrya japonica Lindl.)grown in two open-top growth chambers with CO_2 concentrations of 400 μmol·mol^(-1) and 700 μmol·mol^(-1) were used to assess the effects of elevated atmospheric CO_2 concentration and water stress on the parameters of chlorophyll fluorescence and antioxidative enzymes of the leaves.The experimental result shown that the values of Fv/Fm,Fv/Fo and ΦPSⅡ under the condition of high atmospheric CO_2 concentration (700 μmol·mol^(-1))were obviously higher than that under low atmospheric CO_2 concentration (400 μmol·mol^(-1)),but there were no significant difference between the water-stressed plants and well-watered plants.In addition,increasing atmospheric CO_2 concentration could markedlly enhanced the activities of SOD,POD and CAT,whereas under the condition of water stress,increased range of the activities of SOD,POD and CAT,and the contents of MDA was reduced by applying high atmospheric CO_2 concentration.This means that high CO_2 concentration may have amelioration effect on drought-induced oxidative damage.