紫外辐射对三叶草彩斑蚜3种保护酶活性的影响

Effects of ultraviolet radiation on three types of protective enzymes in Therioaphis trifolii

为了明确紫外辐射对三叶草彩斑蚜体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT) 3种保护酶活性的影响,将其12 h内所产若蚜置于40 W UV-B辐射下分别处理20、30、40、50和60 min,连续照射8代,每代每天照射1次,连续照射6 d后收集虫体用于测定其体内保护酶的活性。结果表明,同一世代三叶草彩斑蚜CAT、SOD活性均随着辐射时间的延长出现先升高后降低的变化趋势,且各处理均显著高于对照(P <0.05),活性最大值分别为同世代对照的12.84和8.05倍;各世代CAT活性均在40 min处理时最高,POD活性除F5代外均在40 min处理时最高,SOD活性除F6代其余世代均在40 min处理时最高。同一处理CAT、SOD和POD活性均随着辐射代数的增加出现先升高后降低的变化趋势,最大值分别为对照的12.84、8.05和2.09倍,CAT和POD酶的活性除30 min处理外,其余处理均在F_6代最高;SOD活性各处理均在F_6代活性最高。以上说明短时间紫外辐射能显著提高三叶草彩斑蚜体内SOD、CAT、POD保护酶的活性,其中CAT、SOD比POD反应明显。

To clarify the effect of ultraviolet radiation(UV-B)on the activity of three protective enzymes(SOD,POD,and CAT)in Therioaphis trifolii,nymphs were exposed to 40 W UV-B radiation for 20,30,40,50,and 60 min within 12 h of hatching.The nymphs were irradiated once a day continuously for 6 days and the activity of the protective enzymes was measured in the last 8 generations subjected to continuous exposure.The study showed that the activity of CAT and SOD first increased and then decreased with the extension of radiation time and the activity in all treated aphids was significantly higher than in the control(P<0.05)in the same generation,and the maximum activity was 12.84 and 8.05 times that of the control,respectively.In each generation at 40 min of exposure,CAT activity was the highest,POD activity was the highest except in the F5 generation,and SOD activity was the highest except in the F6 generation.Secondly,the activity of CAT,SOD,and POD under the same treatment first increased and then decreased with each successive irradiated generation and the maximum activity was 12.84,8.05,and 2.09 times that of the control,respectively.The activity of CAT and POD was the highest in the F6 generation,except at 30 min,and SOD activity was the highest in the F6 generation.These results showed that UV-B can significantly improve the activity of the protective enzymes(P<0.05)in Therioaphis trifolii and that CAT and SOD play a key role under UV-B radiation.