Influence of iridoid glycoside containing host plants on midgut β-glucosidase activity in a polyphagous caterpillar, Spilosoma virginica Fabricius (Arctiidae).
Influence of iridoid glycoside containing host plants on midgut β-glucosidase activity in a polyphagous caterpillar, Spilosoma virginica Fabricius (Arctiidae).
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DOI：
10.1016/j.jinsphys.2010.08.013
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发表时间：
2010-12
影响因子：
2.2
通讯作者：
Helga Pankoke;M. Bowers;S. Dobler
中科院分区：
文献类型：
--
作者：
Helga Pankoke;M. Bowers;S. Dobler
环烯醚萜是一类次生植物化合物，对非适应的草食性昆虫具有威慑、减慢生长甚至毒害作用。为了研究含有环烯醚苷的植物对食草动物消化代谢的影响，用3种不同次生植物化学成分的植物--蒲公英(不含环烯醚苷)、车前(低环烯醇苷含量)和高环烯醚苷含量(高环烯醚苷)，饲养了维吉尼亚蜘蛛幼虫。用不同底物测定了5龄幼虫中肠β-葡萄糖苷酶的活性和动力学性质。取食杉木幼虫的β-葡萄糖苷酶活性显著低于取食药用赤杨的幼虫。4-硝基苯基-β-d-吡喃葡萄糖苷测定结果表明，取食杉木幼虫的DNA-葡萄糖苷酶活性显著低于取食杉木的幼虫。以环烯醇苷桃叶珊瑚苷为底物，我们没有发现三种植物上饲养的幼虫β-葡萄糖苷酶活性的差异。热灭活实验表明，4-硝基苯基-β-d-吡喃葡萄糖苷存在一个不耐热的和一个更热稳定的β-葡萄糖苷酶，其米氏常数相近。我们讨论了在杉木上饲养的幼虫β-葡萄糖苷酶活性降低的可能机制，以及它与通用草食动物适应含有环烯醚萜苷的植物种类的相关性以及它们作为潜在寄主植物的用途。
Iridoid glycosides are secondary plant compounds that have deterrent, growth reducing or even toxic effects on non-adapted herbivorous insects. To investigate the effects of iridoid glycoside containing plants on the digestive metabolism of a generalist herbivore, larvae of Spilosoma virginica (Lepidoptera: Arctiidae) were reared on three plant species that differ in their secondary plant chemistry: Taraxacum officinale (no iridoid glycosides), Plantago major (low iridoid glycoside content), and P. lanceolata (high iridoid glycoside content). Midguts of fifth instar larvae were assayed for the activity and kinetic properties of β-glucosidase using different substrates. Compared to the larvae on T. officinale, the β-glucosidase activity of larvae feeding on P. lanceolata was significantly lower measured with 4-nitrophenyl-β-d-glucopyranoside. Using the iridoid glycoside aucubin as a substrate, we did not find differences in the β-glucosidase activity of the larvae reared on the three plants. Heat inactivation experiments revealed the existence of a heat-labile and a more heat-stable β-glucosidase with similar Michaelis constants for 4-nitrophenyl-β-d-glucopyranoside. We discuss possible mechanisms leading to the observed decrease of β-glucosidase activity for larvae reared on P. lanceolata and its relevance for generalist herbivores in adapting to iridoid glycoside containing plant species and their use as potential host plants.