Early season herbivore differentially affects plant defence responses to subsequently colonizing herbivores and their abundance in the field
Early season herbivore differentially affects plant defence responses to subsequently colonizing herbivores and their abundance in the field
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DOI：
10.1111/j.1365-294x.2008.03838.x
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发表时间：
2008-07-01
影响因子：
4.9
通讯作者：
Dicke, Marcel
中科院分区：
文献类型：
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作者：
Poelman, Erik H.;Broekgaarden, Colette;Dicke, Marcel
早季食草动物对植物防御的诱导可以调节种间草食动物的竞争。我们通过不同生物整合水平的研究，研究了三种草食性昆虫之间由植物介导的竞争。我们讨论了(I)基因表达；(Ii)昆虫在实验室条件下的行为和表现；以及(Iii)田间条件下的种群动态。我们研究了菜粉蝶毛虫对甘蓝属植物早期食草性反应中编码胰酶抑制因子的基因和参与硫代葡萄糖苷生物合成的基因的表达。此外，我们还研究了这些转录反应与菜青虫和小菜蛾这两种专业食草动物以及多面手菜蛾对次生草食反应的相互作用。菜青虫诱导的反应与植物对次生草食的反应有很强的相互作用。与专家的初级食草动物相比，专业食草动物的顺序摄食导致防御相关基因的表达水平增强或相似。多面手甘蓝根结线虫的次生食草性导致的基因表达水平低于该多面手对初级草食性的反应。菜青虫诱导的植物反应对专业食草动物和一般食草动物的幼虫表现都有负面影响。然而，在田间，专家小菜蛾在菜青虫诱导植株上的数量更多，在产卵实验中更喜欢这些植株而不是未受伤害的植株。相反，多面性油菜根结线虫在对照植物上数量较多，并且喜欢未受危害的植物产卵。菜青霉不区分受同种寄主危害的植物和未受损害的植物。我们的研究表明，早季食草性对参与植物对次生草食动物防御的转录反应有不同的影响，其种群发展取决于寄主植物的专化程度。
Induction of plant defences by early season herbivores can mediate interspecific herbivore competition. We have investigated plant-mediated competition between three herbivorous insects through studies at different levels of biological integration. We have addressed (i) gene expression; (ii) insect behaviour and performance under laboratory conditions; and (iii) population dynamics under field conditions. We studied the expression of genes encoding a trypsin inhibitor and genes that are involved in glucosinolate biosynthesis in response to early season herbivory by Pieris rapae caterpillars in Brassica oleracea plants. Furthermore, we studied the interaction of these transcriptional responses with responses to secondary herbivory by the two specialist herbivores, P. rapae and Plutella xylostella, and the generalist Mamestra brassicae. P. rapae-induced responses strongly interacted with plant responses to secondary herbivory. Sequential feeding by specialist herbivores resulted in enhanced or similar expression levels of defence-related genes compared to primary herbivory by specialists. Secondary herbivory by the generalist M. brassicae resulted in lower gene expression levels than in response to primary herbivory by this generalist. Larval performance of both specialist and generalist herbivores was negatively affected by P. rapae-induced plant responses. However, in the field the specialist P. xylostella was more abundant on P. rapae-induced plants and preferred these plants over undamaged plants in oviposition experiments. In contrast, the generalist M. brassicae was more abundant on control plants and preferred undamaged plants for oviposition. P. rapae did not discriminate between plants damaged by conspecifics or undamaged plants. Our study shows that early season herbivory differentially affects transcriptional responses involved in plant defence to secondary herbivores and their population development dependent upon their degree of host plant specialization.