Detection of Differential Host Susceptibility to the Marine Oomycete Pathogen Eurychasma dicksonii by Real-Time PCR: Not All Algae Are Equal
Detection of Differential Host Susceptibility to the Marine Oomycete Pathogen Eurychasma dicksonii by Real-Time PCR: Not All Algae Are Equal
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DOI：
10.1128/aem.01885-08
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发表时间：
2009-01-15
影响因子：
4.4
通讯作者：
Kuepper, Frithjof C.
中科院分区：
文献类型：
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作者：
Gachon, Claire M. M.;Strittmatter, Martina;Kuepper, Frithjof C.
在海洋环境中，越来越多的证据表明，寄生虫是控制种群动态和整个生态系统结构的关键角色。然而，它们的流行程度和对海洋大型藻类群落的影响实际上仍不清楚。事实上，海藻的传染病在很大程度上没有得到充分的记录，部分原因是用显微镜诊断它们所需的专业知识。然而，在过去的几年里，实时定量聚合酶链式反应(QPCR)已经成为监测病原体的视觉症状评分的一种快速和可靠的替代方法。因此，我们在这里提出了一种适合于检测和定量其胞外和片胞褐藻宿主中的卵菌病原菌Dicksonii的定量聚合酶链式反应方法。对实验室控制培养物进行的qPCR和显微镜观察表明，克隆褐藻菌株对Euryachma表现出不同程度的抗性，从高度敏感到完全没有症状不等。这一观察结果有力地证明了褐藻抗病基因决定论的存在，这将对自然种群的动态和遗传结构产生广泛的影响。我们还利用qPCR对采集于北欧和南美的丝状褐藻中的Euryachma进行了快速检测，发现该方法具有特异性、稳定性和广泛的现场适用性。因此，本研究开启了大规模田间病害监测与实验室对照实验相结合的前景，对基因组模式海藻Etocarpus silicosus进行了研究，以提高我们对褐藻病害的认识。
In the marine environment, a growing body of evidence points to parasites as key players in the control of population dynamics and overall ecosystem structure. However, their prevalence and impact on marine macroalgal communities remain virtually unknown. Indeed, infectious diseases of seaweeds are largely underdocumented, partly because of the expertise required to diagnose them with a microscope. Over the last few years, however, real-time quantitative PCR (qPCR) has emerged as a rapid and reliable alternative to visual symptom scoring for monitoring pathogens. Thus, we present here a qPCR assay suitable for the detection and quantification of the intracellular oomycete pathogen Eurychasma dicksonii in its ectocarpalean and laminarialean brown algal hosts. qPCR and microscopic observations made of laboratory-controlled cultures revealed that clonal brown algal strains exhibit different levels of resistance against Eurychasma, ranging from high susceptibility to complete absence of symptoms. This observation strongly argues for the existence of a genetic determinism for disease resistance in brown algae, which would have broad implications for the dynamics and genetic structure of natural populations. We also used qPCR for the rapid detection of Eurychasma in filamentous brown algae collected in Northern Europe and South America and found that the assay is specific, robust, and widely applicable to field samples. Hence, this study opens the perspective of combining large-scale disease monitoring in the field with laboratory-controlled experiments on the genome model seaweed Ectocarpus siliculosus to improve our understanding of brown algal diseases.