基于比较基因组学分析海洋聚球藻对铁限制的适应机制  

Adaptive mechanisms of iron limitation on the marine Synechococcus based on comparative genomics

作　　者：穆蓉 朱珠[1] 张瑞峰[1] MU Rong;ZHU Zhu;ZHANG Ruifeng(School of Oceanography,Shanghai Jiao Tong University,Shanghai 200030,China)

机构地区：[1]上海交通大学海洋学院,上海200030

出　　处：《热带海洋学报》2023年第6期89-100,共12页Journal of Tropical Oceanography

基　　金：国家自然科学基金委重大项目课题(41890801);科技部政府间国际合作重点专项(2022YFE0136500)。

摘　　要：铁在海水中溶解度低,来源有限,是全球40%海域中浮游植物的主要生长限制因子。海洋聚球藻是一种全球分布的超微型蓝藻,也是海洋初级生产力最主要的贡献者之一。受到近岸和大洋环境中铁来源和浓度的影响,海洋聚球藻应对铁限制的适应机制可能存在差异。本研究基于29株全基因组测序的海洋聚球藻进行了比较基因组学分析。结果表明,海洋聚球藻具有较高的遗传多样性,隶属于GTDB(Genome TaxonomyDatabase)分类法中Cyanobiaceae科的4个属,并且这4个属与原有NCBI(National Center for Biotechnology Information)分类法中海洋聚球藻的亚群分类具有很好的对应关系。功能注释结果表明,近岸和大洋聚球藻的特有基因数量与种类差异较大,近岸株中参与无机离子转运和代谢的特有基因数量大于大洋株。进一步分析海洋聚球藻铁限制相关基因后发现,近岸株在铁的吸收、稳态调节和储存方面的能力强于大洋株,对环境变化的感知和响应能力也更强。本研究重新梳理了海洋聚球藻的进化关系和分类地位,并系统分析了近岸和大洋聚球藻基因组及应对铁限制的适应机制差异,为深入理解海洋聚球藻的环境适应性提供了依据。Low solubility and limited source of iron in seawater are the main growth limiting factors for phytoplankton in 40%of the global ocean.Marine Synechococcus is a picocyanobacteria with global distribution and is one of the most important contributors to marine prime productivity.Affected by the source and concentration of iron in coastal and oceanic environments,marine Synechococcus has different adaptive mechanisms to iron limitation.In this study,we performed a comparative genomic analysis of 29 whole genome sequenced marine Synechococcus.The results showed that marine Synechococcus had high genetic diversity and belonged to four genera of Cyanobiaceae under the GTDB(Genome Taxonomy Database)taxonomy,and these four genera corresponded well to the subtype under NCBI(National Center for Biotechnology Information)taxonomy.The results of functional annotation showed that the number and types of unique genes differed between coastal and oceanic Synechococcus,and unique gene of coastal strains are more involved in inorganic ion transport and metabolism.Further analysis of iron limitation-related genes in marine Synechococcus revealed that the coastal strain had stronger abilities of iron uptake,homeostasis regulation and storage than the oceanic strains,and had a better ability to sense and respond to environmental changes.In this study,we reviewed the evolutionary relationships and taxonomic positions of marine Synechococcus using comparative genomics,and identified the differences in the genome and adaptive mechanisms of coastal and oceanic strains in response to iron limitation,to provide a basis for better understanding of the environmental adaptation of marine Synechococcus.

关 键 词：比较基因组学 海洋聚球藻 铁限制 适应机制 

分 类 号：Q943[生物学—植物学]