Wu Guo-Zhao, Hu Lin, Ye Mao, Wang Rui-Long, Zhu Ke-Yan, Zeng Ren-Sen, Cai Wen
State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou 510642, China.
Ying Yong Sheng Tai Xue Bao. 2012 Jul;23(7):1952-8.
In a long history of interactions between insects and plants, plants have developed various anti-insect compounds and defense signaling transduction pathways to defend against herbivorous insects, while insects have responded with sophisticated detoxification enzyme systems to protect against the toxicity of anti-insect compounds. In this study, the 2nd or 3rd instar of Spodoptera litura larvae were successively fed with the diets containing 0.5% soybean trypsinase inhibitor (SBTI) for six generations to evaluate the effects of SBTI and defense signaling compounds on the activities of detoxification enzymes carboxylesterase (CarE) and glutathione-S-transferase (GST) in the midgut and fatbody of the larvae. After fed with the diets, the CarE and GST activities in the 5th instar larvae increased significantly. The CarE activity in the midgut and fatbody of the second generation larvae was the highest, being 2.06 and 2.40 times, and 1.96 and 2.70 times of that of the control, and the GST activity in the midgut and fatbody of the fourth and second generations was the highest, being 7.03 and 11.58 times, and 5.71 and 3.60 times of that of the control, respectively. These induced enzyme activities decreased gradually when the larvae continuously grew with the SBTI-containing diets. In addition, when the S. litura larvae were pre-exposed to methyl jasmonate (MeJA) or methyl salicylate (MeSA) for 48 h or fed with the diets containing 0.5% SBTI, the activities of CarE and GST in the midgut and fatbody increased significantly, and, when the 2nd instar larvae were pre-exposed to MeJA and MeSA for 48 h, the effects of SBTI on the GST activity in larval midgut and fatbody were reduced.
在昆虫与植物漫长的相互作用历史中，植物已形成各种抗虫化合物和防御信号转导途径来抵御植食性昆虫，而昆虫则以复杂的解毒酶系统作为回应，以抵御抗虫化合物的毒性。在本研究中，将斜纹夜蛾幼虫的二龄或三龄幼虫连续六代喂食含0.5%大豆胰蛋白酶抑制剂（SBTI）的饲料，以评估SBTI和防御信号化合物对幼虫中肠和脂肪体中解毒酶羧酸酯酶（CarE）和谷胱甘肽 - S - 转移酶（GST）活性的影响。喂食饲料后，五龄幼虫中的CarE和GST活性显著增加。第二代幼虫中肠和脂肪体中的CarE活性最高，分别是对照的2.06倍和2.40倍，以及1.96倍和2.70倍；第四代和第二代幼虫中肠和脂肪体中的GST活性最高，分别是对照的7.03倍和11.58倍，以及5.71倍和3.60倍。当幼虫继续以含SBTI的饲料生长时，这些诱导的酶活性逐渐下降。此外，当斜纹夜蛾幼虫预先暴露于茉莉酸甲酯（MeJA）或水杨酸甲酯（MeSA）48小时或喂食含0.5% SBTI的饲料时，中肠和脂肪体中的CarE和GST活性显著增加，并且，当二龄幼虫预先暴露于MeJA和MeSA 48小时时，SBTI对幼虫中肠和脂肪体中GST活性的影响降低。
