Virally induced mortality of Phaeocystis globosa during two spring blooms in temperate coastal waters
Virally induced mortality of Phaeocystis globosa during two spring blooms in temperate coastal waters
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DOI：
10.3354/ame044207
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发表时间：
2006-10-10
影响因子：
1.4
通讯作者：
Brussaard, Corina P. D.
中科院分区：
文献类型：
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作者：
Baudoux, Anne-Claire;Noordeloos, Anna A. M.;Brussaard, Corina P. D.
本研究报告病毒介导的死亡率在北海南部的球形棕囊藻单细胞在2个连续的春季开花（2003年和2004年）。一个适应的稀释方法被用来估计病毒裂解和微型浮游动物同时放牧。用30 kDa超滤液（无病毒和食草动物稀释剂）和0.2 pra过滤海水（无食草动物，但含病毒稀释剂）进行平行稀释实验。在自然条件下孵育24 h后，根据2个稀释系列之间球形假单胞菌生长速率的差异计算比病毒裂解率。该方法的有效性使用已知的球形疟原虫病毒（PgV）感染的球形疟原虫培养物进行了测试。野外数据表明，病毒引起的死亡率可能是球形棕囊藻单细胞的一个重要损失因子（高达0.35 d（-1）），与微型浮游动物摄食（高达0.4 d（-1））相当。病毒裂解是导致球形棕囊藻细胞裂解的主要原因。假设没有由于下沉造成的损失，病毒裂解占球形红球藻单细胞总死亡率的5%至66%。病毒裂解和总推定的PgV丰度增加伴随着丰富的球形假单胞菌单细胞，而感染性PgV的增加被延迟。这种延迟可能是由于球形假单胞菌菌落破裂时产生的透明外聚合物颗粒的形成引起的，并且已知其被动吸附病毒。病毒和微型浮游动物被证明是主要的控制代理人的P. globosa单细胞，虽然他们的相对重要性变化的过程中的盛开和年之间。
This study reports virally mediated mortality rates of Phaeocystis globosa single cells in the southern North Sea during 2 consecutive spring blooms (2003 and 2004). An adapted dilution method was used to estimate viral lysis and microzooplankton grazing simultaneously. Parallel dilution experiments were performed with 30 kDa ultrafiltrate (virus and grazer-free diluent) and 0.2 pra filtered seawater (grazer-free, but virus-containing diluent). Specific viral lysis rates were calculated from the difference in P. globosa growth rates between the 2 dilution series after 24 h incubation under natural conditions. The validity of this method was tested using a culture of P. globosa infected with a known P. globosa virus (PgV). The field data show that virally induced mortality can be a substantial loss factor for P. globosa single cells (up to 0.35 d(-1)), comparable to that due to microzooplankton grazing (up to 0.4 d(-1)). Viral lysis was the major cause of total P. globosa cell lysis. Assuming no loss due to sinking, viral lysis accounted for 5 to 66 % of the total mortality of R globosa single cells. Viral lysis and total putative PgV abundance increased concomitantly with abundance of P. globosa single cells whilst the increase in infective PgV was delayed. This delay may be caused by the formation of transparent exopolymeric particles that are generated when P. globosa colonies disrupt and are known to passively adsorb viruses. Viruses and microzooplankton were shown to be major controlling agents of P. globosa single cells, although their relative significance varied over the course of the bloom and between years.