Herbivore-specific, density-dependent induction of plant volatiles: honest or "cry wolf" signals?
Herbivore-specific, density-dependent induction of plant volatiles: honest or "cry wolf" signals?
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DOI：
10.1371/journal.pone.0012161
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发表时间：
2010-08-17
期刊：
影响因子：
3.7
通讯作者：
Takabayashi J
中科院分区：
文献类型：
--
作者：
Shiojiri K;Ozawa R;Kugimiya S;Uefune M;van Wijk M;Sabelis MW;Takabayashi J
植物在受到草食性节肢动物的攻击时会释放挥发性化学物质。它们通常以剂量依赖的方式这样做：食草动物越多，释放的挥发物越多。挥发物吸引捕食性节肢动物，其数量决定捕食者响应的概率。我们表明，幼苗的甘蓝品种（甘蓝变种。capitata，cv Shikidori）对甘蓝白色（Pieris rajiata）幼虫的密度也表现出这种反应，并且当植物上有更多的食草动物时，吸引更多的（幼稚）寄生蜂（Cotesia glomerata）。然而，当攻击小菜蛾（小菜蛾）幼虫，幼苗相同的品种（CV Shikidori）释放挥发物，其总量是高的和恒定的，因此独立的毛虫密度，和天真的寄生虫（Cotesia vestalis）小菜蛾幼虫未能区分食草动物丰富的食草动物穷人的植物。相反，另一个甘蓝品种B的幼苗。oleracea（var.无头畸形：甘蓝）对小菜蛾幼虫密度的反应呈剂量依赖性，且在食草动物较多时吸引更多的寄生蜂。假设这些反应的卷心菜品种反映了至少一些基因型的野生植物的行为，我们提供的论点，为什么羽衣甘蓝（B。oleracea var acephala）被最好地解释为诚实的信号传导策略，并且卷心菜cv Shikidori（B.甘蓝（oleracea var capitata）作为一种“狼来了”信号策略，这意味着植物与其食草动物的敌人之间的利益冲突：植物从被食草动物的敌人访问中获利，但后者通过访问其他食草动物更多的植物会更好。如果是这样的话，进化论的警报信号预测的后果主要利益的学生的植物保护，三营养系统和通信等。
Plants release volatile chemicals upon attack by herbivorous arthropods. They do so commonly in a dose-dependent manner: the more herbivores, the more volatiles released. The volatiles attract predatory arthropods and the amount determines the probability of predator response. We show that seedlings of a cabbage variety (Brassica oleracea var. capitata, cv Shikidori) also show such a response to the density of cabbage white (Pieris rapae) larvae and attract more (naive) parasitoids (Cotesia glomerata) when there are more herbivores on the plant. However, when attacked by diamondback moth (Plutella xylostella) larvae, seedlings of the same variety (cv Shikidori) release volatiles, the total amount of which is high and constant and thus independent of caterpillar density, and naive parasitoids (Cotesia vestalis) of diamondback moth larvae fail to discriminate herbivore-rich from herbivore-poor plants. In contrast, seedlings of another cabbage variety of B. oleracea (var. acephala: kale) respond in a dose-dependent manner to the density of diamondback moth larvae and attract more parasitoids when there are more herbivores. Assuming these responses of the cabbage cultivars reflect behaviour of at least some genotypes of wild plants, we provide arguments why the behaviour of kale (B. oleracea var acephala) is best interpreted as an honest signaling strategy and that of cabbage cv Shikidori (B. oleracea var capitata) as a “cry wolf” signaling strategy, implying a conflict of interest between the plant and the enemies of its herbivores: the plant profits from being visited by the herbivore's enemies, but the latter would be better off by visiting other plants with more herbivores. If so, evolutionary theory on alarm signaling predicts consequences of major interest to students of plant protection, tritrophic systems and communication alike.