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.

海洋在确定世界气候方面起着重要作用。这部分是由于氧气的产生以及称为植物浮游生物的小光合作用植物消耗二氧化碳。在远离海岸的海洋中部地区，非常小的单细胞蓝细菌是浮游植物中最多的部分。这些蓝细菌正在不断增长和分裂，但它们也不断消耗。有两个主要过程有助于消耗这些细胞。首先，它们可以被病毒感染和杀死，其次可以被称为生物的小单细胞放牧动物用作食物。这是这两个死亡过程之间的相互作用，以及蓝细菌所发展的防御机制，这是该研究项目的重点。我们想找出这些蓝细菌在其表面上是否具有特定的结构，使它们不吸引人作为放牧者的食物。病毒也可能会改变他们感染的细胞，使其没有吸引力，因为食物否则病毒也会被食用。在海洋的大多数地区，没有足够的营养来使蓝细菌的营养成分，重要的是要找出饥饿如何影响其被病毒放牧和感染的易感性。