Resin to Propolis: Biological origins and role in honey bee social immunity and health

在生产树脂的植物和利用它们的各种生物之间，进化出了许多引人入胜的生态相互作用。这项研究将探索蜜蜂如何选择和开发树脂的药理特性，以利于蜂群的健康。蜜蜂是当地和农业生态系统中最重要的传粉者。自2006年以来，美国平均每年损失超过30%的蜜蜂群体，因此，促进蜜蜂的自然防御和养蜂业的经济健康是很重要的。蜜蜂收集树脂，并将其存放在被称为蜂胶的巢中。蜂巢内壁衬里的蜂胶信封起到了环绕蜂群的外部抗菌层的作用，有利于蜜蜂的免疫防御和蜂群级的社会免疫。这项研究将探索树脂中的植物衍生化学成分是否对蜜蜂的一般微生物和特定病原体提供重要的群体防御。此外，它还将确定蜜蜂在受到细菌病原体攻击后是否增加树脂收集和/或将植物来源的树脂转换为具有更大生物活性的树脂来源。将追求四个目标：1)确定蜂胶包膜是否对细菌病原体--幼虫--美国污育病的病原体--具有活性。这些发现将揭示促进蜜蜂健康的新方法，并解释自然收集的化合物在减轻蜜蜂疾病方面的作用。2)量化蜜蜂是否增加了树脂收集以响应细菌病原体的挑战。这些研究将揭示蜂群中相对罕见的蜜蜂亚群收集树脂的行为机制，这些蜜蜂的觅食选择有助于群体层面的社会免疫。3)通过代谢物指纹图谱分析确定蜂胶配方所用树脂的植物来源。这些分析的结果将确定生物活性物质的来源与它们对蜜蜂健康的最终影响之间的联系。这一联系将为未来研究全球蜜蜂亚种之间树脂使用和健康之间的关系提供洞察力。4)使用生物测定驱动的纯化和基于代谢组学的方法鉴定蜂胶中抑制蜜蜂细菌病原体生长的生物活性成分。现代生物测定导向的化学分离将有助于发现以前未知的抗菌物质，并为树脂在植物-动物相互作用的生态学和进化中作为药理学试剂的作用开辟新的研究途径。这项研究将吸引和教育从应用养蜂到代谢组学和分子遗传学等学科的学生。通过与威斯康星大学河瀑布分校的生物学教授合作，参加蜜蜂课程(蜜蜂增强教育)的本科生将分析蜂胶处理过的蜂群中的蜜蜂病毒水平，这将帮助他们将微生物学、生态学、植物学和分子生物学的概念与传粉者衰退的相关“现实世界”问题联系起来。PI的研究、教学和推广相结合的任命确保了这项研究将被翻译并传播给不同的受众，包括科学家、传统和非传统学生、养蜂人和普通公众。

A number of fascinating ecological interactions have evolved between resin producing plants and the wide array of organisms that exploit them. This research will explore how honey bees, Apis mellifera, select and exploit the pharmacological properties of resin to benefit the health of the colony. Honey bees are the most important pollinators of native and agro-ecosystems. Due to the average annual loss of over 30% of the U.S. honey bee colonies since 2006, it is important to promote the natural defenses of honey bees and the economic health of the beekeeping industry. Honey bees collect resin and deposit it in the nest where it is called propolis. A propolis envelope lining the inner walls of the nest acts as an external antimicrobial layer surrounding the colony, benefiting bee immune defenses and colony-level social immunity. This research will explore if plant-derived chemical components in resin provide an important colony defense against both general microorganisms and specific pathogens of honey bees. Further it will determine if bees increase resin collection and/or switch botanical sources of resin to those with greater biological activity after challenge with a bacterial pathogen. Four objectives will be pursued: 1) Determine if the propolis envelope is active against the bacterial pathogen, Paenibacillus larvae, the causative agent of American foulbrood disease in field colonies. Findings will reveal novel approaches to promote honey bee health and explain the function of naturally collected compounds in mitigating diseases of honey bees. 2) Quantify if honey bees increase resin collection in response to challenge with a bacterial pathogen. These studies will shed light on the behavioral mechanisms underlying the collection of resin by a relatively rare subset of bees in the colony whose foraging choices contribute to social immunity at the colony level. 3) Identify the botanical sources of resins used by honey bees for propolis formulation by metabolite fingerprinting analysis. Findings from these analyses will establish the link between the origin of the biologically active substances and their ultimate impacts on honey bee health. This link will provide insight for future studies into the relationship between resin use and health among honey bee subspecies across the globe. 4) Identify bioactive components of propolis that inhibit growth of a honey bee bacterial pathogen using both bioassay-driven purification and metabolomics-based methods. Modern bioassay-guided chemical isolation will facilitate the discovery of previously unknown antimicrobial substances and open new research avenues into the role of resins as pharmacological agents in the ecology and evolution of plant-animal interactions. This research will attract and educate students in disciplines from applied beekeeping to metabolomic analyses and molecular genetics. Through a collaboration with Biology professors at the University of Wisconsin, River Falls, undergraduates participating in the BEE course (Bees Enhancing Education) the will analyze virus levels in bees from propolis-treated colonies, which will help them connect microbiology, ecology, botany, and molecular biology concepts to the relevant, "real-world" problem of pollinator decline. The PI's combined research, teaching, and extension appointments ensure that this research will be translated and disseminated to a diverse audience including scientists, traditional and non-traditional students, beekeepers, and the general public.