CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France.
MIVEGEC, Univ Montpellier, IRD, CNRS, Montpellier, France.
Sci Rep. 2020 Jun 22;10(1):10071. doi: 10.1038/s41598-020-66655-w.
In several highly specialized plant-insect interactions, scent-mediated specificity of pollinator attraction is directed by the emission and detection of volatile organic compounds (VOCs). Although some plants engaged in such interactions emit singular compounds, others emit mixtures of VOCs commonly emitted by plants. We investigated the chemical ecological bases of host plant recognition in the nursery pollination mutualism between the dioecious Ficus carica and its specific pollinator Blastophaga psenes. Using Y-tube olfactometer tests, we show that B. psenes females are attracted by VOCs of receptive figs of both sexes and do not exhibit preference for VOCs of either male or female figs. Electrophysiological tests and chemical analysis revealed that of all the VOCs emitted by receptive figs, only five were found to be active on female antennae. Behavioural tests show that, in contrast to VOCs presented alone, only a blend with a particular proportion of four of these VOCs is as attractive as the odour of receptive figs, and that if there is a very small change in this blend proportion, the pollinator is no longer attracted. This study revealed that in highly specialized mutualistic interactions specificity could be mediated by a particular blend of common compounds emitted by plants.
在几种高度专业化的植物-昆虫相互作用中，由挥发性有机化合物（VOCs）的释放和检测来指导传粉者吸引的气味介导的特异性。尽管一些参与此类相互作用的植物释放单一化合物，但其他植物则释放植物通常释放的 VOC 混合物。我们研究了雌雄异株的榕属植物 Ficus carica 和其特定传粉者 Blastophaga psenes 之间苗圃传粉共生关系中宿主植物识别的化学生态基础。使用 Y 型管嗅觉计测试，我们表明 B. psenes 雌性被两性接受榕的 VOC 吸引，并且对雄性或雌性榕的 VOC 没有偏好。电生理测试和化学分析表明，在接受榕释放的所有 VOC 中，只有五种被发现对雌性触角有活性。行为测试表明，与单独呈现的 VOC 相比，只有这些 VOC 中的四种以特定比例混合的混合物才与接受榕的气味一样有吸引力，如果这种混合物的比例有很小的变化，传粉者就不再被吸引。这项研究表明，在高度专业化的互利共生关系中，特异性可以由植物释放的特定混合物来介导。
