植物源次生物质棉酚和芸香苷对绿盲蝽保护酶与解毒酶活性的影响

为明确棉酚和芸香苷2种植物次生物质对绿盲蝽Apolygus lucorum体内3种保护酶——过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)和3种解毒酶——碱性磷酸酶(AKP)、酸性磷酸酶(ACP)、谷胱甘肽S-转移酶(GST)的影响,通过在人工饲料中添加棉酚和芸香苷饲喂不同龄期绿盲蝽若虫,分别在24、48、72 h后测定若虫体内保护酶和解毒酶的活性。结果表明,同一龄期的绿盲蝽若虫取食不同浓度的同种外源次生物质后,随着次生物质浓度的升高,3种保护酶活性分别在不同浓度处理下达到最大值,如1龄若虫其CAT活性在0.4 mg/mL棉酚胁迫下达到最大,为72.8 U/mg protein,SOD和POD活性分别在0.8 mg/mL棉酚胁迫下达到最大,为59.8、23.0 U/mg protein,而3种解毒酶ACP、AKP和GST活性则均在0.4 mg/mL棉酚胁迫下达到最大,分别为26.9、29.5、66.8 U/mg protein,即绿盲蝽受到不同浓度外源次生物质胁迫后,体内的保护酶和解毒酶被激活的程度不同。同一龄期若虫取食不同种类的次生物质后,体内同一种保护酶的活性变化也不尽相同,如3龄若虫其SOD活性在1.0 mg/mL棉酚或0.04 mg/mL芸香苷胁迫48 h后均达到最大,分别为58.0 U/mg protein或61.1 U/mg protein,且显著高于其它浓度胁迫,即不同种类次生物质诱导绿盲蝽同一种保护酶达到最大值所需浓度不同。表明绿盲蝽受到不同种类外源次生物质或者不同浓度同种外源次生物质胁迫后,体内保护酶和解毒酶活性的变化是一个复杂的过程,且不同酶的变化处于一种协调状态,以适应外界环境条件的变化。

Effects of plant secondary metablites gossypol and rutin on the activities of protective enzymes and detoxification enzymes in green mirid bug Apolygus lucorum

In order to clarify the effects of two kinds of plant secondary metablites on three protective enzymes and three detoxifying enzymes in green mirid bug Apolygus lucorum, gossypol or rutin was added into the artificial diet to feed the mirid nymph. The activities of the three protective enzymes, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and three detoxifying enzymes, acid phosphate (ACP), alkaline phosphate (AKP), glutathione S-transferase (GST), were measured on 24, 48, and 72 h after the nymph feeding the diet. The results showed that the activities of different protective enzymes or detoxifying enzymes in the same instars of A. lucorum needed different concentrations of the same secondary metablite to reach the maximum. For example, CAT in the 1st instar nymph of A. lucorum reached the maximal activity 72.8 U/mg protein under 0.4 mg/mL gossypol; however, SOD and POD activities reached the maximum 59.8 U/mg protein and 23.0 U/mg protein under 0.8 mg/mL gossypol. The three detoxifying enzymes, ACP, AKP, and GST, reached the maximum activity under 0.8 mg/mL gossypol, which were 26.9, 29.5, and 66.8 U/mg protein, respectively. The degrees of activation of protective enzymes and detoxification enzymes in the nymphs of A. lucorum were different after exposure to different degrees of exogenous stress. The activity of the same protective enzyme or detoxifying enzyme in the same instar nymph of A. lucorum was also differently activated by different kinds of secondary metablites. SOD in the 3rd instar nymph of A. lucorum reached its maximal activity 58.0 U/mg protein or 61.1 U/mg protein on 48 h after eating the artificial food containing 1.0 mg/mL gossypol or 0.04 mg/mL rutin. Both of the maximal activities were significantly different from those at other concentrations. The same protective enzyme in the nymph of A. lucorum needed different concentrations of secondary metablites to reach the maximum activity. To adapt the varied external environment conditions, the change in activities of the protective enzymes or detoxifying enzymes was complicated and in a coordinated mode after the nymph of A. lucorum suffering from different kinds of exogenous substances or one kind of substance with different concentrations.