Reduction in photosystem II efficiency during a virus-controlled Emiliania huxleyi bloom
Reduction in photosystem II efficiency during a virus-controlled Emiliania huxleyi bloom
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DOI：
10.3354/meps10527
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发表时间：
2014-01-01
影响因子：
2.5
通讯作者：
Wilson, William H.
中科院分区：
文献类型：
--
作者：
Kimmance, Susan A.;Allen, Michael J.;Wilson, William H.
在艾米利亚赫胥黎病毒感染期间，实验室研究表明，光系统 (PS) II 效率在感染后几天内下降，并被认为与病毒引起的光系统之间电子传输速率的中断有关。然而，测量病毒感染对来自自然的、分类学上多样化的浮游植物群落的赫胥黎惠氏鲍鱼PSII功能的影响是困难的，而且这种现象是否在自然界中发生目前尚不清楚。在这里，叶绿素荧光分析用于评估在挪威海岸附近的中生态系统实验期间整个赫胥黎桉水华中 PSII 效率的变化。具体来说，我们的目的是确定是否可以观察到由于天然赫胥黎大肠杆菌群体的病毒感染而对 PSII 光化学效率产生可测量的抑制。在水华崩溃前的主要感染期，PSII效率显着降低，最大PSII光化学效率（F-v/F-m）平均下降17%，最大PSII有效吸收截面（sigma(PSII)）相应增加75%；与此同时，赫胥黎大肠杆菌生长率显着下降，赫胥黎大肠杆菌（EhV）产量增加。由于赫胥黎桉种群在浮游植物群落中占主导地位，并可能贡献了叶绿素库的 100%，因此我们认为，在此期间测量的可变叶绿素荧光信号主要来自赫胥黎桉，因此反映了赫胥黎桉细胞内发生的变化。这是首次证明在天然颗石藻群体的病毒感染过程中发生 PSII 光化学抑制。
During viral infection of Emiliania huxleyi, laboratory studies have shown that photo system (PS) II efficiency declines during the days post-infection and is thought to be associated with viral-induced interruption of electron transport rates between photosystems. However, measuring the impact of viral infection on PSII function in E. huxleyi populations from natural, taxonomically diverse phytoplankton communities is difficult, and whether this phenomenon occurs in nature is presently unknown. Here, chlorophyll fluorescence analysis was used to assess changes in PSII efficiency throughout an E. huxleyi bloom during a mesocosm experiment off the coast of Norway. Specifically, we aimed to determine whether a measurable suppression of the efficiency of PSII photochemistry could be observed due to viral infection of the natural E. huxleyi populations. During the major infection period prior to bloom collapse, there was a significant reduction in PSII efficiency with an average decrease in maximum PSII photochemical efficiency (F-v/F-m) of 17% and a corresponding 75% increase in maximum PSII effective absorption cross-section (sigma(PSII)); this was concurrent with a significant decrease in E. huxleyi growth rates and an increase in E. huxleyi virus (EhV) production. As E. huxleyi populations dominated the phytoplankton community and potentially contributed up to 100% of the chlorophyll a pool, we believe that the variable chlorophyll fluorescence signal measured during this period was derived predominantly from E. huxleyi and, thus, reflects changes occurring within E. huxleyi cells. This is the first demonstration of suppression of PSII photochemistry occurring during viral infection of natural coccolithophore populations.