Mukanganyama S, Figueroa C C, Hasler J A, Niemeyer H M
University of Zimbabwe, Department of Biochemistry, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe.
J Insect Physiol. 2003 Mar;49(3):223-9. doi: 10.1016/s0022-1910(02)00269-x.
The presence of glutathione transferases and esterase activity was investigated in Rhopalosiphum padi and the effects of the cereal hydroxamic acid, 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) on these detoxification enzymes was studied. Activity of glutathione S-transferases and general esterases was determined for adult aphids feeding on a natural diet lacking DIMBOA and on an artificial DIMBOA-containing diet for 48 hours. In vivo, DIMBOA in the diet inhibited the activities of esterases by 50-75% at all concentrations tested (0.5-4 mM). The activity of glutathione transferase was inhibited to a lesser extent (30%) at the higher concentrations of DIMBOA. In vitro, DIMBOA generally inhibited the activity of esterases with an IC(50) of 33 micro M, and had a slight inhibitory effect on glutathione S-transferases. These effects of DIMBOA could make the aphids vulnerable to electrophilic agents and insecticides which may be metabolized via esterases and GSTs. In cereals, therefore, DIMBOA may act by interfering with esterase- or GST-mediated detoxification of xenobiotics by aphids.
研究了禾谷缢管蚜中谷胱甘肽转移酶和酯酶活性，并研究了谷物异羟肟酸2,4 - 二羟基 - 7 - 甲氧基 - 1,4 - 苯并恶嗪 - 3 - 酮（DIMBOA）对这些解毒酶的影响。测定了以缺乏DIMBOA的天然饲料和含人工DIMBOA的饲料喂养48小时的成年蚜虫的谷胱甘肽S - 转移酶和一般酯酶的活性。在体内，饲料中的DIMBOA在所有测试浓度（0.5 - 4 mM）下均能使酯酶活性抑制50 - 75%。在较高浓度的DIMBOA下，谷胱甘肽转移酶的活性受到较小程度的抑制（30%）。在体外，DIMBOA通常以33 μM的IC（50）抑制酯酶活性，并对谷胱甘肽S - 转移酶有轻微抑制作用。DIMBOA的这些作用可能使蚜虫易受亲电试剂和杀虫剂的影响，这些试剂可能通过酯酶和谷胱甘肽S - 转移酶进行代谢。因此，在谷物中，DIMBOA可能通过干扰蚜虫对异源物质的酯酶或谷胱甘肽S - 转移酶介导的解毒作用来发挥作用。
Zotero 插件