Chemical Coevolution of Animals and Plants

为了促进种子的传播，肉质果实进化为吸引动物使用各种适应性，如含糖奖励和丰富多彩的展示。动物进化到利用诸如糖的吸引力和颜色视觉等适应性来利用肉质水果。近年来，我们的工作提供了证据表明，水果气味-成熟水果散发出的挥发性化学物质的香味-可能是一种信号，其功能是促进种子传播，而不是水果成熟的愉快副产品。此外，我们发现了可能来自糖的化学物质，因此是动物和植物之间化学通讯进化的底物。然而，这些观察仍然是基于生态快照，因此，植物是否真的进化到通过化学信号发出成熟信号还不得而知。此外，鉴于在这项工作之前，野生成熟水果气味的化学成分几乎是未知的，因此不知道种子传播者的嗅觉是否进化到利用水果化学信号。因此，虽然人们知道果实性状驱动植物的传播，物种形成和多样化，但化学通讯-动物-植物相互作用的关键因素-在驱动植物和动物共同进化中的作用仍然是黑暗的。使用无花果和狐猴作为模型系统，拟议的项目将在三个单元解决这些问题。第一个将使用生态学，化学，遗传学和转录组学方法来确定水果气味已经进化为种子传播者的诚实信号。第二部分将使用比较生理学来确定，选择吃水果的动物是为了对植物使用的化学物质做出反应。第三个单元将使用系统发育的方法来建立化学通讯如何驱动植物地理学。因此，该项目将研究动物和植物如何共同进化以使用化学信号进行交流，以及这一过程如何在空间和时间上推动植物进化。

To promote seed dispersal, fleshy fruits evolved to attract animals using various adaptations like sugary rewards and colorful displays. Animals evolved to exploit fleshy fruits using adaptations such as attraction to sugar and color vision. In recent years, our work provided evidence that fruit scent - the bouquet of volatile chemicals emitted by ripe fruits - is likely to be a signal whose function is to facilitate seed dispersal, as opposed to a pleasant byproduct of fruit maturation. Moreover, we identified chemicals which are likely to derive from sugar and thus be the substrate on which chemical communication between animals and plants has evolved. Yet these observations are still based on ecological snapshots, and it is therefore unknown whether plants have indeed evolved to signal ripeness through chemical signals. Moreover, given that before this work the chemistry of wild ripe fruit scent was almost unknown, it is unknown whether seed dispersers’ sense of smell evolved to utilize fruit chemical signals. As a result, while it is known that fruit traits drive plant dispersal, speciation and diversification, the role of chemical communication - a critical factor in animal-plant interaction - in driving plant and animal coevolution has remained in the dark. Using figs and lemurs as a model systems, the proposed project will address these questions in three units. The first will use ecological, chemical, genetic and transcriptomic approaches to establish that fruit scent has evolved as an honest signal to seed dispersers. The second will use comparative physiology to establish that fruit-eating animals are selected to respond to the chemicals plants use as signals. The third unit will use a phylogenetic approach to establish how chemical communication has driven plant biogeography. As such, the project will study how animals and plants have co-evolved to communicate using chemical signals, and how this process drove plant evolution in space and time.