Mortality of marine picoplankton: viral infection, protistan grazing, bacterial cell defence interactions

海洋超微型浮游生物的死亡率：病毒感染、原生生物放牧、细菌细胞防御相互作用

• 批准号: NE/D011817/1
• 负责人: Nicholas Mann
• 金额: $ 6.18万
• 依托单位: NATIONAL OCEANOGRAPHY CENTRE
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FD011817%2F1
• 关键词: Mortality; marine; picoplankton; viral; infection

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 small photosynthetic plants called phytoplankton. In the large central regions of the oceans, away from the coasts, very small unicellular cyanobacteria are the most numerous part of the phytoplankton. 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 would like to find out whether these cyanobacteria have specific structures on their surfaces that make them unattractive as food for the grazers. It is also possible that viruses alter the cells that they have infected to make them unattractive as food otherwise the virus would also get eaten. In most parts of the oceans there aren't enough nutrients for the cyanobacteria and it is important to find out how starvation affects their susceptibility to being grazed and infected by viruses.

海洋在决定世界气候方面发挥着重要作用。这部分是由于被称为浮游植物的小型光合植物产生氧气和消耗二氧化碳。在远离海岸的海洋中心区域，非常小的单细胞蓝藻是浮游植物中数量最多的部分。这些蓝藻不断生长和分裂，但它们也不断被消耗。有两个主要过程有助于这些细胞的消耗。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。这是这两个死亡过程之间的相互作用，以及蓝细菌已经开发的防御机制，这是本研究项目的重点。我们想知道这些蓝藻的表面是否有特殊的结构，使它们作为食草动物的食物没有吸引力。病毒也有可能改变它们感染的细胞，使它们作为食物失去吸引力，否则病毒也会被吃掉。在海洋的大部分地区，没有足够的营养素供蓝藻生长，重要的是要弄清楚饥饿如何影响它们对被放牧和被病毒感染的敏感性。