Protistan grazing and viral infection of marine picoplankton: a role for the host cell surface?

海洋超微型浮游生物的原生生物放牧和病毒感染：宿主细胞表面的作用？

基本信息

批准号：
NE/J02273X/1
负责人：
David Scanlan
金额：
$ 43.02万
依托单位：
University of Warwick
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FJ02273X%2F1
关键词：
Protistan grazing viral infection marine

项目摘要

The oceans play a major role in determining the world's climate. In part this is due to the production of oxygen and the consumption of carbon dioxide by very small, single celled organisms, which are referred to as the photosynthetic picoplankton. Marine cyanobacteria of the closely-related genera Prochlorococcus and Synechococcus are the prokaryotic components of the photosynthetic picoplankton. These cyanobacteria are continually growing and dividing, but they are also continuously being consumed. There are two major processes that contribute to the consumption of these cells. Firstly, they can be infected and killed by viruses and secondly they can be used as food by small single celled grazing animals called protists. It is the interaction between these two processes of mortality, together with the defence mechanisms that the cyanobacteria have developed, which are the focus of this research project. We recently observed that a marine Synechococcus strain that was infected with a virus was more susceptible to grazing than the uninfected culture. This distinct preference for preying on phage-infected cells has potentially important ecological implications, as it interferes with phage proliferation by removing infected cells before they burst and could thus indirectly reduce phage abundance. It is not yet clear what determines the palatability of a prey cell. Cell surface properties are likely to play a role and we have preliminary evidence that lipopolysaccharide (LPS) components of the cell wall are critical in this respect. This proposal will thus compare protist feeding on virus-infected, uninfected and LPS-modified Synechococcus strains in order to specifically elucidate the role of LPS in prey digestibility. Moreover, we will extend our studies to the Atlantic Ocean to investigate whether cultured protists graze differentially on natural Synechococcus populations, and in so doing establish the role of strain selectivity, or preference for cyanophage-infected cells, in this processOverall, the project will provide fundamentally new mechanistic information on the major biological loss processes that dictate the growth rate and yield of a key marine photoautotroph, information which is critical for defining and understanding controls on marine photosynthesis.

海洋在决定世界气候方面发挥着重要作用。部分原因是非常小的单细胞生物（被称为光合超微型浮游生物）产生氧气并消耗二氧化碳。密切相关的原绿球藻属和聚球藻属的海洋蓝藻是光合超微型浮游生物的原核成分。这些蓝藻不断生长和分裂，但它们也不断被消耗。有两个主要过程导致这些细胞的消耗。首先，它们可以被病毒感染和杀死；其次，它们可以被称为原生生物的小型单细胞食草动物用作食物。这两个死亡过程之间的相互作用，以及蓝藻所发展的防御机制，是该研究项目的重点。我们最近观察到，感染病毒的海洋聚球藻菌株比未感染的培养物更容易放牧。这种捕食噬菌体感染细胞的独特偏好具有潜在的重要生态意义，因为它通过在受感染的细胞破裂之前去除它们来干扰噬菌体增殖，从而间接减少噬菌体丰度。目前尚不清楚是什么决定了猎物细胞的适口性。细胞表面特性可能发挥作用，我们有初步证据表明细胞壁的脂多糖（LPS）成分在这方面至关重要。因此，该提案将比较原生生物以病毒感染、未感染和 LPS 修饰的聚球藻菌株为食，以具体阐明 LPS 在猎物消化率中的作用。此外，我们将把我们的研究扩展到大西洋，以调查培养的原生生物是否以不同的方式吃天然聚球藻种群，并在此过程中确定菌株选择性或对噬藻体感染细胞的偏好的作用。总的来说，该项目将提供关于决定关键海洋光合自养生物生长速率和产量的主要生物损失过程的全新机制信息，这些信息对于定义和理解海洋光合作用的控制至关重要。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Spontaneous Deletion of an "ORFanage" Region Facilitates Host Adaptation in a "Photosynthetic" Cyanophage.

DOI：
10.1371/journal.pone.0132642
发表时间：
2015
期刊：
PloS one
影响因子：
3.7
作者：
Puxty RJ;Perez-Sepulveda B;Rihtman B;Evans DJ;Millard AD;Scanlan DJ
通讯作者：
Scanlan DJ

Trade-offs of lipid remodeling in a marine predator-prey interaction in response to phosphorus limitation.

DOI：
10.1073/pnas.2203057119
发表时间：
2022-09-06
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
影响因子：
11.1
作者：
Guillonneau, Richard;Murphy, Andrew R. J.;Teng, Zhao-Jie;Wang, Peng;Zhang, Yu-Zhong;Scanlan, David J.;Chen, Yin
通讯作者：
Chen, Yin

Relative stability of ploidy in a marine Synechococcus across various growth conditions.

海洋聚球藻倍性在各种生长条件下的相对稳定性。