Chemical Coevolution of Animals and Plants

为了促进种子的传播，肉质的水果进化成通过各种适应来吸引动物，比如含糖的奖励和彩色的展示。动物进化到利用诸如对糖的吸引力和色觉等适应来利用肉质水果。近年来，我们的工作提供了证据，证明水果气味-成熟水果散发出的挥发性化学物质的气味-可能是一种信号，其功能是促进种子传播，而不是水果成熟时令人愉快的副产品。此外，我们还发现了可能来自糖的化学物质，从而成为动物和植物之间化学交流进化的基础。然而，这些观察结果仍然是基于生态快照，因此尚不清楚植物是否确实进化到通过化学信号来发出成熟信号。此外，考虑到在这项工作之前，野生成熟水果气味的化学成分几乎是未知的，因此尚不清楚种子传播者的嗅觉是否进化到利用水果的化学信号。因此，虽然已知果实性状驱动植物的扩散、物种形成和多样化，但化学通讯（动物与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未知的。以无花果和狐猴为模型系统，拟建项目将用三个单元来解决这些问题。第一种方法将使用生态学、化学、遗传学和转录组学方法来证明，水果气味已经进化成一种可靠的信号，可以传递给种子传播者。第二部分将使用比较生理学来证明，选择吃水果的动物来对植物作为信号的化学物质做出反应。第三单元将使用系统发育方法来建立化学通讯如何驱动植物生物地理学。因此，该项目将研究动物和植物如何共同进化到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.