南海北部与DMSP降解相关的Roseobacter类群的分子生态学研究

Roseobacter类群是海洋中占优势的微生物种群，其对DMSP(β-二甲基巯基丙酸内盐)的降解作用对海洋生态系统生产力以及全球气候变化等方面有着重要的作用。但是对于Roseobacter类群在海洋生态系统中的结构及活性规律仍缺乏足够的认识，其在DMSP含量丰富的近海中的生态功能及其响应机制尚不清楚。本项目瞄准这一前沿问题，以Roseobacter类群中DMSP裂解酶基因dddP和去甲基化基因dmdA为分子靶标，从RNA水平出发，结合克隆文库、高通量测序和定量PCR等分子生物学技术，以南海北部典型区域为研究对象，通过耦合分析各种环境因素，明确Roseobacter类群在该区域的群落结构及代谢活性的规律，深入探讨其在热带近海DMSP降解中的作用机制。本项目将为深入了解这一微生物类群在海洋生源硫转化中的作用机制提供科学依据，为进一步揭示其在海洋生态系统中的重要地位和作用提供新的认识。

Roseobacter clade is dominated in the marine system, which play important role for the productivity of marine ecosystem and global climate change through dimethylsulfoniopropionate (DMSP) degradation. Although some of the research has focused on the ocean area, it was unclear about its ecological functions and response to DMSP transformation in the marine system, especially in the coastal areas which are rich in DMSP. In this project, DMSP lyase gene (dddP) and DMSP demethylation gene (dmdA) were acted as molecular marker. Combined with clone libraries, high throughput sequencing and quantitative PCR, the study was to assess the roles of Roseobacter clade in DMSP degradation based on the RNA level. Representative region, such as the Pearl River freshwater, Luzon Strait, upwelling zones and area far from the coast, will be focused in the study. By coupling analysis of various environmental factors, it will be clear about Roseobacter clade structure, its number and its metabolic activity in the northern South China Sea. Further, the DMSP degradation mechanism of Roseobacter clade will be verified in the tropical coastal seawater. To study the molecular ecology of Roseobacter clade in the tropical sea, not only provide invaluable data of its ecological functions in coastal waters, but also help us to understand the potential mechanisms of Roseobacter clade in DMSP degradation as well as providing new insight of the important roles in the marine ecosystem.