二斑叶螨危害对棉花应激防御酶活性的影响

摘要

The effects of Tetraychus urticae damage on stress defense-enzymes activity of cotton was compared in the paper . In the stage of 5-6 leaves of cotton seedlings inoculated different amount ( 10-40) of female adults, feeding 1 -4 d after picking leaf of different treatment, using spectrophotometer determination of catalase ( CAT ) , peroxidase ( POD ) , polyphenol oxidase ( PPO ) and lipoxygenase ( LOX) and phenylalanine aminolyase ( PAL) activity of the enzyme, the influence of Tetranychus urticae on stress of defensive enzyme activity was vertified. The results showed that after the mites feeding, the cotton leaf CAT activity increased significantly, and with the increase of induction time, activity change offered a tendency of upgrading firstly then descending latter. When harmed for 3 d, 10, 20, 40 head/leaf CAT activity peaked and significantly higher than control ( P <0. 05 ); POD, PAL activity increased following the increase of induction time extension and mite population. The peak occurred when harmed for 4 d. PPO, LOX activity offered a upgrade tendency following the increase of time firstly than descending latter. Peak occurred when harmed for 2 d and still significantly higher than control. Cotton leaf stress defense enzyme activity increased following harm time and mites population. It indicated that the mite herbivore stress can induce host plant to produce a series of biochemical reactions. Different enzyme activity performance made differently.%探明二斑叶螨取食对棉花叶片内应激防御性酶活性的影响。在棉苗5-6叶期接种不同数量(10-40头)的二斑叶螨雌成虫,取食1-4 d后采摘不同处理的叶片,利用分光光度计测定过氧化氢酶( CAT )、过氧化物酶( POD)、多酚氧化酶( PPO)、脂氧合酶( LOX)和苯丙氨酸解氨酶( PAL)活性。结果表明二斑叶螨取食后,棉花叶片CAT活性显著升高,且随诱导时间的延长其活性变化呈先上升后下降的趋势,为害3 d时,10、20、 H (每株接棉蚜跟叶螨各40头)头/叶的CAT活性达到最高峰,显著高于对照( P<0．05)； POD、 PAL活性也随诱导时间的延长和螨口数量的增加呈上升趋势,为害4 d时达到最高峰；而PPO、 LOX活性随着时间的增加呈现上升后下降趋势,且为害2 d时达到最高峰,仍显著高于对照( P<0．05)。棉叶应激防御酶活性随着二斑叶螨为害时间与螨口密度的增加而增加,表明二斑叶螨的危害胁迫能诱导寄主植物产生一系列应激生化反应,不同的酶活性表现有所不同。