2,4-D丁酯对罂粟(Papaver somniferum L.)保护酶活性及脂质过氧化作用的影响

Effect of 2,4-D on the antioxidative enzyme activities and lipid peroxidation in Opium Poppy(Papaver somniferum L.)

罂粟(Papaver somniferum L.)花蕾期用不同浓度的2,4-D丁酯对植株进行处理,测定了4d中叶片相对含水量(RWC)、丙二醛(MDA)含量、膜相对透性及保护酶(SOD、POD)活性变化情况。结果表明:在1ml/L、2ml/L、4ml/L浓度处理下对罂粟叶片RWC影响不显著,8ml/L处理下的RWC随处理时间的延长呈显著下降趋势,第4天比第1天下降了48.7%。在各处理下MDA含量和膜相对透性的变化趋势基本一致,1ml/L、2ml/L、4ml/L处理前期下降,后期升高。8ml/L处理对MDA含量和膜相对透性的影响显著的高于其它处理,随处理时间的延长呈先升高后降低的趋势。保护酶在处理条件下随时间延长其活性有明显的变化:POD活性变化波动较大,除8ml/L外其它处理在第2、第4天有两次上升峰,8ml/L峰值出现在第2天,之后下降在第4天达最低。SOD活性先降低后升高,都高于对照,所有处理SOD活性在第3d最低,第4天8ml/L处理的活性显著的高于其它处理。表明了高浓度(8ml/L)的2,4-D能使膜脂过氧化而产生较大的损伤,其它浓度处理对膜脂过氧化及膜透性影响相对较小,表明8ml/L的2,4-D是灭杀罂粟的最适用量。

Changes in RWC,MDA content and the activities of SOD and POD in Opium Poppy were measured at the bud stage treated by different concentrations of 2,4-D.RWC was affected insignificantly by 1ml/L,2ml/L and 4ml/L 2,4-D treatment,but RWC decreased significantly in 8ml/L treatment and RWC was 48.7% lower 4d post treatment than 1d post treatment.The changes in the MDA content and the cell membrane electrolyte leakage showed the same trend with different treatments.The MDA content and cell membrane electrolyte leakage decreased in the early stage then increased under 1ml/L,2ml/L and 4ml/L treatment.In contrast,the MDA content and cell membrane electrolyte leakage increased in the early stage then decreased under the 8ml/L treatment.The activities of SOD and POD varied among treatments.POD activities increased at 2 or 4d post treatment except for the 8ml/L treatment,in which POD activities increased at 2d and decreased at 4d post treatment.SOD activities decreased in the early stage and increased in the later stage,and its activities were significantly higher in the treatments than in the CK.These results suggested that a high concentration（8ml/L）2,4-D treatment caused damage to the Opium Poppy cells by lipid peroxidation,whereas lower concentrations were less effective.