Mesophotic coral depth acclimatization is a function of host-specific symbiont physiology
Mesophotic coral depth acclimatization is a function of host-specific symbiont physiology
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中光珊瑚深度适应是宿主特异性共生生理学的函数
DOI：
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发表时间：
2015
影响因子：
3.7
通讯作者：
C. Voolstra
中科院分区：
文献类型：
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作者：
M. Ziegler;Cornelia M. Roder;C. Büchel;C. Voolstra
中光珊瑚生态系统因其在全球环境变化时期作为深层珊瑚避难所的潜力而受到越来越多的关注。在这里，研究了红海中部 60 m 深度梯度的珊瑚全生物光适应机制，研究了滨珊瑚属、细珊瑚属、厚珊瑚属和波达巴西亚珊瑚属四个珊瑚属的情况。一般的适应策略对于所有宿主-共生体组合都是通用的，例如共生藻细胞密度和光保护与光捕获色素的比例均随着水深的增加而显着降低。滨珊瑚在整个 60 m 深度范围内都含有 C15 型共生藻，而 Pachyseris 和 Podabacia 的垂直分布有限，主要为 C1 型共生藻。共生藻 C15 型通常比 C1 具有更高的叶黄素脱环氧化速率和更低的最大量子产率，并且在深度上也表现出强烈的光适应信号，这与滨珊瑚的大分布范围有关。有趣的是，珊瑚宿主对共生藻色素成分有影响。当比较 Podabacia 和 Pachyseris 中的 C1 型共生藻时，宿主物种之间的 s-胡萝卜素 Chl a-1、多甲素 Chl a-1 和二甲藻黄素 Chl a-1 比率存在显着差异。我们的数据支持这样一种观点，即珊瑚在中光度下的深度适应得到了共生藻生理学的支持，而共生藻生理学又是宿主特异性的。
Mesophotic coral ecosystems receive increasing attention owing to their potential as deep coral refuges in times of global environmental change. Here, the mechanisms of coral holobiont photoacclimatization over a 60 m depth gradient in the central Red Sea were examined for the four coral genera Porites, Leptoseris, Pachyseris, and Podabacia. General acclimatization strategies were common to all host-symbiont combinations, e.g. Symbiodinium cell densities and photoprotective to light-harvesting pigment ratios both significantly decreased with water depth. Porites harboured Symbiodinium type C15 over the whole 60 m depth range, while Pachyseris and Podabacia had limited vertical distributions and hosted mainly Symbiodinium type C1. Symbiodinium type C15 had generally higher xanthophyll de-epoxidation rates and lower maximum quantum yields than C1, and also exhibited a strong photoacclimatory signal over depth that relates to the large distribution range of Porites. Interestingly, the coral host had an effect on Symbiodinium pigment composition. When comparing Symbiodinium type C1 in Podabacia and Pachyseris, the s-carotene chl a-1, the peridinin chl a-1, and diadinoxanthin chl a-1 ratios were significantly different between host species. Our data support a view that depth acclimatization of corals in the mesophotics is supported by Symbiodinium physiology, which in turn is host-specific.