Novel lineages of Prochlorococcus and Synechococcus in the global oceans
Novel lineages of Prochlorococcus and Synechococcus in the global oceans
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全球海洋中原绿球藻和聚球藻的新谱系
DOI：
10.1038/ismej.2011.106
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发表时间：
2012-02-01
期刊：
影响因子：
11
通讯作者：
Chen, Feng
中科院分区：
文献类型：
--
作者：
Huang, Sijun;Wilhelm, Steven W.;Chen, Feng
以原绿球藻和聚藻球菌为代表的Picocyanobacteria在海洋固碳和养分循环中具有重要作用。本研究基于16S-23S rRNA内部转录间隔段（ITS）序列，比较了从河口到开阔海域、热带到极地海洋、表层到深水等不同海洋生态系统中picocyanobacteria的群落组成。从20个样本中恢复的1339个ITS序列揭示了原绿球藻和聚藻球菌的多种和几种以前未知的分支。鉴定出6个高光（HL）适应原绿球藻分支，其中HLVI分支以前未被描述过。在赤道太平洋样品中检测到的原绿球藻枝HLIII、HLIV和HLV可能与最近在高营养、低叶绿素（HNLC）、缺铁的热带海洋中发现的HNLC枝有关。在亚热带开阔海域和南海发现了至少4个新的聚囊球菌分支（共6个分支），隶属于亚群5.3。在聚球菌亚群5.3中观察到随深度的生态位划分。在高纬度水域（白令海北部和楚科奇海），聚囊球菌亚群5.2的成员占主导地位，表明该亚群中的某些海洋聚囊球菌可能具有冷适应性。从白令海到楚科奇海，微蓝菌群落有明显的转移，这反映了水温的变化。我们的研究表明，海洋系统包含大量不同的picocyanobacteria，并进一步表明，随着先进的测序技术对微生物联合体的探索，新的picocyanobacteria基因型或生态型将继续出现。
Picocyanobacteria represented by Prochlorococcus and Synechococcus have an important role in oceanic carbon fixation and nutrient cycling. In this study, we compared the community composition of picocyanobacteria from diverse marine ecosystems ranging from estuary to open oceans, tropical to polar oceans and surface to deep water, based on the sequences of 16S-23S rRNA internal transcribed spacer (ITS). A total of 1339 ITS sequences recovered from 20 samples unveiled diverse and several previously unknown clades of Prochlorococcus and Synechococcus. Six high-light (HL)-adapted Prochlorococcus clades were identified, among which clade HLVI had not been described previously. Prochlorococcus clades HLIII, HLIV and HLV, detected in the Equatorial Pacific samples, could be related to the HNLC clades recently found in the high-nutrient, low-chlorophyll (HNLC), iron-depleted tropical oceans. At least four novel Synechococcus clades (out of six clades in total) in subcluster 5.3 were found in subtropical open oceans and the South China Sea. A niche partitioning with depth was observed in the Synechococcus subcluster 5.3. Members of Synechococcus subcluster 5.2 were dominant in the high-latitude waters (northern Bering Sea and Chukchi Sea), suggesting a possible cold-adaptation of some marine Synechococcus in this subcluster. A distinct shift of the picocyanobacterial community was observed from the Bering Sea to the Chukchi Sea, which reflected the change of water temperature. Our study demonstrates that oceanic systems contain a large pool of diverse picocyanobacteria, and further suggest that new genotypes or ecotypes of picocyanobacteria will continue to emerge, as microbial consortia are explored with advanced sequencing technology.