Biology and evolution of the ascophyllum symbiosis

这项研究计划将研究一种复杂的共生关系，这种共生关系以棕色海藻--结瘤海藻为基础。本种是北大西洋冷温带岩石潮间带海岸的主要光合作用有机体，包括大西洋加拿大沿海的大部分地区。这种共生关系包括：i)一种互惠共生的真菌(MyCophycias Ascophylli)，它总是存在于宿主组织中；ii)一种普通的红藻，它是子囊菌上的专性附生植物；iii)一种专性附生的棕色藻类(Elachista Fucicola)，它通常丰富地存在于子囊菌上；以及iv)迄今所描述的最丰富的海洋昆虫(Halocladius Varablis)，主要局限于Elachista。该研究计划将重点放在这个共生群落的藻类和真菌成分上，利用生态学、生理学和分子工具来了解这些物种之间相互作用的性质。此外，对共生群落整个分布的不同组成部分的分子进化研究将为了解北大西洋和北冰洋的冰后生物地理提供重要的见解。此外，由于Acohyllum是加拿大东部主要的收获和加工工业的基础，因此用于农业应用的最终产品的特性可能来自真菌共生体。这项研究计划将通过与业界(Acadian Seaants Ltd.)的合作来帮助解决这一根本问题。并向他们提供培养。总体而言，这项研究计划将为潮间带生态学提供新的见解，并使子囊菌成为海洋共生的主要模式系统。

This research program will investigate a complex symbiosis based around the brown seaweed, Ascophyllum nodosum. This species is the dominant photosynthetic organism of rocky intertidal shores of the cold-temperate North Atlantic Ocean, including large parts of coastal Atlantic Canada. The symbiosis includes: i) a mutualistic fungus (Mycophycias ascophylli), which is always present in the host tissues; ii) a common red alga that is an obligate epiphyte on Ascophyllum; iii) an obligate epiphytic brown alga (Elachista fucicola) that is often abundant on Ascophyllum; and iv) the most abundant marine insect yet described (Halocladius variabilis), that is largely restricted to Elachista. The research program will focus on the algal and fungal components of this symbiotic community using ecological, physiological and molecular tools to understand the nature of the interactions among these species. In addition, the molecular-evolutionary studies of the different components of the symbiotic community from throughout its distribution will provide important insights into the post-glacial biogeography of the North Atlantic and Arctic Oceans. Furthermore, since Ascophyllum is the basis of a major harvesting and processing industry in eastern Canada, it is possible that properties of the resulting products used in agricultural applications are derived from the fungal symbiont. This research program will help address this fundamental issue by collaborating with industry (Acadian Seaplants Ltd.) and making cultures available to them. Overall, this research program will provide new insights into intertidal ecology, and make Ascophyllum a major model system for marine symbioses.