Van Poecke R M, Posthumus M A, Dicke M
Laboratory of Entomology, Wageningen University, The Netherlands.
J Chem Ecol. 2001 Oct;27(10):1911-28. doi: 10.1023/a:1012213116515.
Many plant species defend themselves against herbivorous insects indirectly by producing volatiles in response to herbivory. These volatiles attract carnivorous enemies of the herbivores. Research on the model plant Arabidopsis thaliana (L.) Heynh. has contributed considerably to the unraveling of signal transduction pathways involved in direct plant defense mechanisms against pathogens. Here, we demonstrate that Arabidopsis is also a good candidate for studying signal transduction pathways involved in indirect defense mechanisms by showing that: (1) Adult females of Cotesia rubecula, a specialist parasitic wasp of Pieris rapae caterpillars, are attracted to P. rapae-infested Arabidopsis plants. (2) Arabidopsis infested by P. rapae emits volatiles from several major biosynthetic pathways, including terpenoids and green leaf volatiles. The blends from herbivore-infested and artificially damaged plants are similar. However, differences can be found with respect to a few components of the blend, such as two nitriles and the monoterpene myrcene, that were produced exclusively by caterpillar-infested plants, and methyl salicylate, that was produced in larger amounts by caterpillar-infested plants. (3) Genes from major biosynthetic pathways involved in volatile production are induced by caterpillar feeding. These include AtTPS10, encoding a terpene synthase involved in myrcene production, AtPAL1, encoding phenylalanine ammonia-lyase involved in methyl salicylate production, and AtLOX2 and AtHPL, encoding lipoxygenase and hydroperoxide lyase, respectively, both involved in the production of green leaf volatiles. AtAOS, encoding allene oxide synthase, involved in the production of jasmonic acid, also was induced by herbivory.
许多植物物种通过在遭受食草动物侵害时产生挥发性物质来间接抵御食草昆虫。这些挥发性物质会吸引食草动物的食肉天敌。对模式植物拟南芥（Arabidopsis thaliana (L.) Heynh.）的研究为揭示植物针对病原体的直接防御机制中涉及的信号转导途径做出了巨大贡献。在此，我们通过以下几点证明拟南芥也是研究间接防御机制中涉及的信号转导途径的良好候选者：（1）菜粉蝶毛虫的专性寄生蜂微红盘绒茧蜂的成年雌蜂会被被菜粉蝶侵害的拟南芥植株所吸引。（2）被菜粉蝶侵害的拟南芥会从几个主要的生物合成途径释放挥发性物质，包括萜类化合物和绿叶挥发物。来自被食草动物侵害和人工损伤植株的混合物是相似的。然而，在混合物的一些成分方面可以发现差异，例如仅由被毛虫侵害的植株产生的两种腈和单萜月桂烯，以及被毛虫侵害的植株产生量更大的水杨酸甲酯。（3）参与挥发性物质产生的主要生物合成途径的基因会被毛虫取食诱导。这些基因包括AtTPS10，其编码参与月桂烯产生的萜烯合酶；AtPAL1，其编码参与水杨酸甲酯产生的苯丙氨酸解氨酶；以及AtLOX2和AtHPL，分别编码脂氧合酶和氢过氧化物裂解酶，二者都参与绿叶挥发物的产生。编码参与茉莉酸产生的丙二烯氧化物合酶的AtAOS也被食草动物侵害诱导。
