Cornell University, Department of Ecology and Evolutionary Biology, Ithaca, New York 14853, USA.
Ecology. 2011 Sep;92(9):1769-80. doi: 10.1890/10-1945.1.
Although induced plant responses to herbivory are well studied as mechanisms of resistance, how induction shapes community interactions and ultimately plant fitness is still relatively unknown. Using a wild tomato, Solanum peruvianum, native to the Peruvian Andes, we evaluated the disruption of pollination as a potential ecological cost of induced responses. More specifically, we tested the hypothesis that metabolic changes in herbivore-attacked plants, such as the herbivore-induced emission of volatile organic compounds (VOCs), alter pollinator behavior and consequentially affect plant fitness. We conducted a series of manipulative field experiments to evaluate the role of herbivore-induced vegetative and floral VOC emissions as mechanisms by which herbivory affects pollinator behavior. In field surveys and bioassays in the plants' native habitat, we found that real and simulated herbivory (methyl jasmonate application) reduced attractiveness of S. peruvianum flowers to their native pollinators. We show that reduced pollinator preference, not resource limitation due to leaf tissue removal, resulted in reduced seed set. Solitary bee pollinators use floral plant volatiles, emitted in response to herbivory or methyl jasmonate treatment, as cues to avoid inflorescences on damaged plants. This herbivory-induced pollinator limitation can be viewed as a general cost of induced plant responses as well as a specific cost of herbivory-induced volatile emission.
虽然植物对食草动物的诱导反应作为一种抵抗机制已经得到了很好的研究,但诱导反应如何塑造群落相互作用并最终影响植物的适合度仍然相对未知。我们使用原产于秘鲁安第斯山脉的野生番茄(Solanum peruvianum)来评估授粉中断是否是诱导反应的潜在生态代价。更具体地说,我们检验了这样一个假设,即受到食草动物攻击的植物的代谢变化,如食草动物诱导挥发的挥发性有机化合物(VOCs),会改变传粉者的行为,并因此影响植物的适合度。我们进行了一系列的野外实验来评估食草动物诱导的营养和花 VOC 排放作为食草动物影响传粉者行为的机制的作用。在植物的自然栖息地的实地调查和生物测定中,我们发现真实和模拟的食草动物(茉莉酸甲酯处理)降低了 S. peruvianum 花对其本地传粉者的吸引力。我们表明,传粉者偏好降低,而不是由于叶片组织去除导致的资源限制,导致种子产量减少。独居蜜蜂传粉者利用花植物挥发物作为避免受损植物花序的线索,这些挥发物是对食草动物或茉莉酸甲酯处理的反应而产生的。这种食草动物诱导的传粉者限制可以被视为诱导植物反应的一般代价,也是食草动物诱导挥发的特定代价。