Disease Resistance in Sea Fan Corals and the Host Range of the Fungal Pathogen

热带海洋生物的发病率似乎在增加，确实有人认为，由于全球变暖和人为原因，发病率将增加。然而，我们缺乏关键的知识来管理热带海洋系统中的疾病。不仅大多数热带海洋病原体，包括广泛研究的珊瑚带病，仍然没有得到确认，而且对甚至已经确认的病原体的抵抗机制也没有得到研究。信息的缺乏尤其成问题，因为没有什么科学依据来制定管理海洋中患病人口的规程。加勒比柳珊瑚中正在发生的真菌流行病为研究突发疾病的动态和宿主抗性机制提供了前所未有的机会。海扇-Aspergillus sydowii的相互作用是非常容易处理的，因为：1）可以通过摄像在二维扇表面上跟踪病变2）真菌可以容易地从自然界中分离，在实验室中培养，并用于抗性研究的生物测定，和3）珊瑚可以在实验室中用纯接种物感染，并在现场通过将患病的嫁接到健康的珊瑚上。本研究的目的是：1）确定病原真菌A的寄主范围;在加勒比海柳珊瑚中， 2)实验研究了海扇菌的抗病机制; 3）研究了温度对海扇菌抗病性和致病力的影响。如果曲霉菌不仅限于柳珊瑚，那么这种流行病可能对加勒比海珊瑚礁产生更大的影响，其中许多珊瑚礁主要由海扇和其他柳珊瑚珊瑚组成。了解自然抗性的机制对于评估新疾病的爆发是否是由新疾病的引入，人为压力导致的珊瑚抵抗力降低或两者兼而有之至关重要。由于病原体的身份是已知的，并在文化中，因为我们能够在实验条件下感染海扇，我们将能够研究宿主防御，病原体动态和环境条件之间的相互作用。

Harvell The incidence of disease among tropical marine organisms appears to be increasing and indeed is thought by some that it will increase due to global warming and anthropogenic causes. Yet we lack critical knowledge to manage disease in tropical marine systems. Not only do most tropical marine pathogens, including the widely studied coral band disease, remain unidentified, but the mechanism of resistance to even identified pathogens is unstudied. The paucity of information is particularly problematic for there is little scientific basis for devising protocols for management of diseased populations in the oceans. An ongoing fungal epizootic among Caribbean gorgonian corals provides an unprecedented opportunity to study the dynamics of an emergent disease and the mechanisms of host resistance. The sea fan-Aspergillus sydowii interaction is unusually tractable because: 1) Lesions can be followed on the 2-dimensional fan surface by videography 2) the fungus can be readily isolated from nature, cultured in the laboratory, and used in bioassay for resistance studies, and 3) corals can be infected in the laboratory with pure inocula and in the field by grafting diseased onto healthy ones. The objectives of this study are to: 1) determine the host range of the fungal pathogen A. sydowii among Caribbean gorgonians, 2) experimentally evaluate the mechanisms of sea fan resistance, and 3) evaluate the role of temperature in disease resistance and pathogen virulence. If Aspergillus is not restricted to Gorgonia, then this epizootic could have far greater impact on Caribbean reefs, many of which are dominated by sea fans and other gorgonian corals. Understanding the mechanisms of natural resistance is important in evaluating whether the spate of new diseases is caused by new disease introductions, lowered resistance of corals due to anthropogenic stresses, or a combination of both. Because the identity of the pathogen is known and in culture, and because we are able to infect sea fan under experimental conditions, we will be able to study the interactions among host defenses, pathogen dynamics, and environmental conditions.