铜绿微囊藻细胞程序性死亡机制及其在水华消亡中的作用研究

项目名称： 铜绿微囊藻细胞程序性死亡机制及其在水华消亡中的作用研究

项目编号： No.41476095

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 徐虹

作者单位： 厦门大学

项目金额： 112万元

中文摘要： 铜绿微囊藻是形成有害水华的主要藻种，由于其水华所造成的危害性而引起了人们的高度重视。目前对水华消亡过程中的分子生物学机制了解不多。我们前期研究发现，在其高密度培养液中有一种死亡信号肽EDF能启动藻细胞进行有毒素-抗毒素系统参与的程序性死亡,从而使培养的藻细胞一夜间全部死亡，这与自然界水华迅速消亡的现象非常相似。因此,为了探究自然界中水华消亡机制，本项目拟从环境信息传递、死亡信号的感应和转导入手，对铜绿微囊藻细胞如何感应EDF信号并启动毒素-抗毒素系统进行程序性死亡的过程进行深入研究，以期揭示水华优势藻种细胞程序性死亡的分子和生理生化机制；并通过水华现场的检测与分析,探究细胞这种程序性死亡大规模启动的机制及其在水华消亡过程中所发挥的作用。这将有助于人们从藻细胞自身编程死亡的全新角度来探讨铜绿微囊藻水华防治的途径，从而及时有效防止水华爆发或使已爆发的水华提前消亡，以避免或减轻水华灾害。

中文关键词： 水华消亡；铜绿微囊藻；细胞程序性死亡；毒素-抗毒素系统；群体感应

英文摘要： Microcystis aeruginosa is one of the most common bloom-forming cyanobacteria in freshwater ecosystems,which can form harmful algal blooms that are of economic and ecological importance. Although an abundance of the published literature has explained the decline of all phytonplankton blooms by a variety of reasons-nutrient depletion, zooplankton grazing and virus infections, the degenerative process and molecular mechanism in algal bloom is still not thoroughly understood. Programmed cell death as a means to bloom temination is a new concept, and not one well understood. In previous research，we identified a quorum-sensing signalextracellular death factor( EDF )in high density culture of Microcystis aeruginosa and proved that EDF could trigger programmed cell death mediated by tonxin-antitoxin system MazEF,which leaded great quantities of cultured Microcystis aeruginosa to die out overnight. The large-scale death of Microcystis aeruginosa is similar to the sudden decline of algal bloom within a short time in the nature. Our research is pointing to the possibility of programmed cell death as a factor in bloom decline. To illuminate the role of programmed cell death triggered by EDF in terminating harmful algal blooms of Microcystis aeruginosa and distinguish factors regulating bloom decline,this project will focus on the process and mechanism of programmed cell death in Microcystis aeruginosa during times of various environmental stresses . To elucide the process and mechanism of programmed cell death, we will study the transduction pathways of death signal EDF and explore its function in enhancing activity of tonxin-antitoxin system MazEF under various environmental stress condtions.To investigate the role of programmed cell death in the decline process of Microcystis bloom , we will monitor the product of death signal EDF and the initiation of programmed cell death at the decline stage in algal bloom of Microcystis aeruginosa. The study will enhance researchers' understanding of the mechanisms of harmful algal bloom termination and the potential for human intervention.

英文关键词： Decline of algal bloom;Microcystis aeruginosa;Programmed cell death;Toxin-antitoxin system;Quorum sensing