RUI: Chemical Signaling among Intertidal Organisms

海洋动植物生活在一个化学信号往往比视觉信号更重要的环境中。水生化学物质为海洋生物提供了关于环境质量、食物、捕食者和配偶位置的关键信息。然而，当退潮时，潮间带植物和动物会花大量时间暴露在空气中，在那里水传播的化学信号是不可用的，但空气传播的化学信号可能很重要。初步数据显示，当它们被食草动物吃掉时，一些潮间带植物会释放出二甲基硫化物，这是一种通过空气传播的化学物质，可以导致附近的植物产生额外的防御食草动物的物质。海洋植物利用空气中的信号化学物质是海洋潮间带生物之间一种新的、潜在的重要通讯机制。因为二甲基硫化物可以被动物探测到，它可以作为一种信号，告诉其他食草动物和它们的捕食者食物或敌人的存在。因此，二甲基硫化物的释放有可能影响整个海洋食物网的相互作用。本项目将使用生化方法测量海洋植物在各种环境条件下释放的二甲基硫化物及其随后在整个环境中的运动。然后将使用各种行为、生理和生态分析来确定空气中的二甲基硫化物对附近植物的防御反应和生长速度的影响，以及食草动物和捕食者的反应和摄食速度的影响。这项研究的结果将提供有关海洋食物网如何运作的基本信息。由于二甲基硫在全球硫循环中很重要，这项研究也将有助于了解硫从海洋到大气的运动。至少八名本科生将协助开展这项工作；因此，该项目将有助于培养下一代海洋科学家。

Marine plants and animals live in an environment where chemical signals are often more important than visual signals. Waterborne chemicals provide marine organisms with critical information about the quality of their environment and the location of food, predators, and mates. However, when the tide is out, intertidal plants and animals spend large amounts of time exposed to air, where waterborne chemical signals are unavailable but airborne chemical signals may be important. Preliminary data has shown that when they are being consumed by grazers, some intertidal plants release dimethyl sulfide, an airborne chemical that can cause nearby plants to produce additional defenses against grazers. This use of airborne signaling chemicals by marine plants is a new and potentially important mechanism of communication among marine intertidal organisms. Because dimethyl sulfide can be detected by animals, it may serve as a signal to other grazers and to their predators about the presence of food or enemies. Thus, the release of dimethyl sulfide has the potential to affect interactions throughout marine food webs. This project will use biochemical methods to measure the release of dimethyl sulfide by marine plants under a variety of environmental conditions and its subsequent movement throughout the environment. A variety of behavioral, physiological, and ecological assays will then be used to determine the effects of airborne dimethyl sulfide on defensive responses and growth rates of nearby plants as well as the responses and feeding rates of herbivores and predators. The results of this study will provide fundamental information about how marine food webs function. Because dimethyl sulfide is important in the global cycling of sulfur, this study will also contribute to knowledge of sulfur movement from the oceans to the atmosphere. At least eight undergraduate students will help conduct this work; therefore, the project will contribute to the training of the next generation of marine scientists.