In vivo quantification of kleptoplastic chlorophyll a content in the “solar-powered” sea slug Elysia viridis using optical methods: spectral reflectance analysis and PAM fluorometry
In vivo quantification of kleptoplastic chlorophyll a content in the “solar-powered” sea slug Elysia viridis using optical methods: spectral reflectance analysis and PAM fluorometry
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使用光学方法对“太阳能”海蛞蝓 Elysia viridis 中盗贼叶绿素 a 含量进行体内定量：光谱反射率分析和 PAM 荧光测定法
DOI：
10.1039/b9pp00058e
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发表时间：
2010
影响因子：
3.1
通讯作者：
R. Calado
中科院分区：
文献类型：
--
作者：
J. Serôdio;Sílvia Pereira;Joana Furtado;Raquel M. Silva;H. Coelho;R. Calado
眼睑成形术是一种特别显著的共生类型，由另一物种宿主组织中功能性叶绿体的存在组成。其中一个研究最充分的类型的窃听器成形术之间的联系，舌蚌软体动物（海蛞蝓）和藻类叶绿体。在摄入后，叶绿体保持光合作用功能并为宿主提供光合产物，因此被称为“太阳能”海蛞蝓。本研究评估了两种光学方法的使用，光谱反射分析和体内Chl荧光，通过脉冲振幅调制（PAM）荧光法测量，在体内定量大藻Codium tomentosum var. mucronatum (G. Hamel) ardr<s:1>的sacoglossan Elysia viridis （Montagu, 1804）叶绿体中kleptoplastic叶绿素（Chl） a的含量。将绿芽孢杆菌标本的Chl a含量与若干基于反射率的指标和暗级荧光f_o进行了比较。在整个色素含量变化范围内，大多数反射率指标与共生叶绿素含量呈线性变化。以750 nm处的反射率为参考，各指标之间的相关性最显著（P < 0.001），色素含量在63.5% ~ 85.9%之间变化。f_o仅在低色素水平（低于4-6 μg Chl a）时与Chl a含量呈线性变化，高于此水平时呈饱和模式。通过监测标本在饥饿和随后的恢复期间Chl - a含量的变化来说明光学方法的使用。本研究结果表明，如果信号检测的基本要求和可重复的测量几何形状得到验证，这些光学方法可能很容易应用于其他光合共生。
Kleptoplasty is a particularly remarkable type of symbiosis, consisting of the presence of functional chloroplasts in the tissues of a host of another species. One of the most well-studied types of kleptoplasty is the association between sacoglossan molluscs (sea slugs) and algal chloroplasts. After ingestion, the chloroplasts remain photosynthetically functional and provide photosynthates to the host, therefore named as “solar-powered” sea slugs. This study evaluated the use of two optical methods, spectral reflectance analysis and in vivo Chl fluorescence, as measured by pulse amplitude modulated (PAM) fluorometry, for the in vivo quantification of kleptoplastic chlorophyll (Chl) a content in the sacoglossan Elysia viridis (Montagu, 1804) bearing chloroplasts of the macroalgae Codium tomentosum var. mucronatum (G. Hamel) Ardré. The Chl a content of E. viridis specimens was compared to a number of reflectance-based indices and to the dark-level fluorescence, F _o. Most reflectance-based indices varied linearly with the symbiosis Chl a content over the whole range of pigment content variation. Most significant correlations ( P < 0.001) were found between indices using as reference the reflectance at 750 nm, with the proportion of pigment content explained by the indices varying between 63.5% and 85.9%. F _o varied linearly with the Chl a content only for low pigment levels (below 4–6 μg Chl a per individual), above which it followed a saturation-like pattern. The use of optical methods was illustrated by monitoring the changes in Chl a content of specimens during periods of starvation and subsequent recovery. The results of this study suggest that, if basic requirements of signal detection and reproducible measuring geometry are verified, these optical methods may be readily applied to other photosynthetic symbioses.