Effect of viral infection on sinking rates of Heterosigma akashiwo and its implications for bloom termination
Effect of viral infection on sinking rates of Heterosigma akashiwo and its implications for bloom termination
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DOI：
10.3354/ame037001
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发表时间：
2004-11-02
影响因子：
1.4
通讯作者：
Suttle, CA
中科院分区：
文献类型：
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作者：
Lawrence, JE;Suttle, CA
病毒在海洋微生物生态中扮演着许多重要的角色，包括浮游植物的致死因子。沉积物中病毒的广泛存在，加上观察到一些鞭毛藻在受到感染时失去了活力，促使我们对感染细胞的命运和感染在原地种群中的传播进行了调查。我们使用了两种感染赤潮异弯藻的无关病毒作为模型系统。用沉淀柱测定病毒感染对赤潮鱼垂直运动的影响。在感染HaRNAV263和赤潮毒株OIS1后的24 h内，20.9+/-5.8和12.2+/-1.9%的种群分别以1.25和0.73md(-1)的速度下沉。到感染后48小时，感染这两种病毒的细胞中约有50%已经裂解。由于下沉细胞在自然环境中会遇到光照水平的下降，我们将感染的细胞在完全黑暗的环境中培养，并比较了裂解周期的长度与L：D周期下培养的细胞的裂解周期的长度。同样，无论光照条件或病毒类型如何，大约50%的种群在48小时前裂解，整个种群的裂解在144小时完成。基于这些结果，我们提出，根据水柱的特征，来自原位感染细胞的病毒有三种可能的命运。在混合层较深(>；8m)的水体中，感染细胞在混合层内发生裂解，并在真光层内传播。如果水相对较深(100米)，而混合层较浅(
Viruses play many important roles in the ecology of marine microbes, including that of mortality agents of phytoplankton. The widespread abundance of viruses in sediments, coupled with observations that some flagellated algae lose motility when infected, prompted this investigation into the fate of infected cells and the propagation of infection throughout a population in situ. We used 2 unrelated viruses that infect the bloom-forming alga Heterosigma akashiwo as model systems. Settling columns were used to determine the impact of viral infection on the vertical movement of H. akashiwo. Within 24 h following infection with HaRNAV 263 or H. akashiwo virus strain OIs1, 20.9 +/- 5.8 and 12.2 +/- 1.9% of the populations were sinking at rates of 1.25 and 0.73 m d(-1), respectively. By 48 h post-infection approximately 50% of cells infected with either virus had lysed. As sinking cells would encounter decreasing levels of light in the natural environment, we incubated infected cultures in complete darkness and compared the length of the lytic cycle to that of cultures incubated under a L:D cycle. Again, approximately 50% of the population lysed by 48 h, regardless of the light conditions or type of virus, and lysis of the entire population was complete by 144 h. Based on these results, we propose that, depending on the characteristics of the water column, there are 3 potential fates for viruses from cells infected in situ. In water with a deep mixed layer (>8 m), lysis of infected cells would occur within the mixed layer and the infection would be propagated within the euphotic zone. If the water is relatively deep (100s of meters), and the mixed layer shallow (