外源物质对干旱复水平邑甜茶抗氧化酶的影响

以苹果砧木平邑甜茶2a生实生苗为材料进行盆栽试验,研究比较了干旱复水条件下外源甜菜碱(GB)、脱落酸(ABA)和硝普纳(SNP,NO供体)对平邑甜茶幼苗抗氧化防护酶活性的影响。结果表明:外源GB、ABA和NO显著降低了干旱胁迫下平邑甜茶幼苗叶片质膜相对透性和MDA含量,重度胁迫时与CK相比,分别降低了13.5%、12.2%、18.4%与32.4%、14.4%、37.6%;外源GB、ABA和NO提高了叶片中SOD、CAT和POD的活性,在田间持水量30%时分别达到最大,与同期CK相比,POD活性分别增加13.5%、13.4%和24.4%,SOD活性分别增加15.3%、13.7%和16.2%,CAT活性则分别增加63.2%、53.7%和95.3%,之后酶活性开始下降。外源GB、ABA处理后GR、DHAR、APX和MDHAR的变化趋势与CAT等趋势相同,同样在田间持水量30%时酶活分别达到最大;NO处理后,GR、DHAR、APX的变化趋势亦相同,虽然NO对MDHAR活性比干旱处理有所升高,但差异不显著。复水后,不同外源物质下植物的抗旱生理指标变化趋势不尽相同。表明喷施外源GB、ABA和NO可有效的提高叶片的抗氧化系统酶的活性,增强平邑甜茶幼苗的抗旱能力。比较GB、ABA和NO处理,NO在提高平邑甜茶抗旱性方面效果最好,GB处理其次,ABA处理最低。

Effect of Exogenous Substances on Antioxidant Protection Enzyme Activity of Drought Stress and Rewater for Malus hupehensis

An experiment was set up,the effect of exogenous GB,ABA and NO to the antioxidant protection enzyme activity after drought and rewater using two-year-old Malus hupehensis for materials were studied and compared.The results showed that exogenous GB,ABA and NO significantly reduced the relative membrane permeability and MDA content in leaves of Malus hupehensis after drought stress and rewater.Compared with CK,in severe drought,the relative membrane permeability and MDA content respectively decreased by 13.5%,12.2%,18.4% and 32.4%,14.4%,37.6%;exogenous GB,ABA and NO improved the activities of SOD,CAT and POD in leaves of Malus hupehensis,in field moisture capacity 30% they respectively achieved the maximum,compared with the same period CK,POD activity respectively increased by 13.5%,13.4% and 24.4%,SOD activity respectively increased by 15.3%,13.7% and 16.2%,CAT activity respectively increased by 63.2%,53.7% and 95.3%,then the enzyme activity decreased.Exogenous GB,ABA treatment made the DHAR,APX,GR,MDHAR activity and the CAT activity had a same changing trends,also in field moisture capacity 30% they respectively achieve the maximum;exogenous NO treatment also made the DHAR,APX,GR activity had the same change tendency,although NO treatment made the MDHAR activity higher than the single drought treatment,but not reached significant differences.After rewater,the variation tendencies of the drought resistance and physiological indexes of Malus hupehensis was the same,which treaded with the different exogenous substances.The results clearly explained that exogenous GB,ABA and NO can effectively increase the antioxidant protection enzyme activity of the leaves,enhance the drought resistance of Malus hupehensis.Comparison between GB,ABA and NO treatment showed that,in the improvement of drought resistance of Malus hupehensis,NO treatment was the best one,GB treatment was next,ABA was the last one.