title: Shifts in archaeaplankton community structure along ecological gradients of Pearl Estuary.
abstract: The significance of archaea in regulating biogeochemical processes has led to an interest in their community compositions. Using 454 pyrosequencing, the present study examined the archaeal communities along a subtropical estuary, Pearl Estuary, China. Marine Group I Thaumarchaeota (MG-I) were predominant in freshwater sites and one novel subgroup of MG-I, that is MG-Iν, was proposed. In addition, the previously defined MG-Iα II was grouped into two clusters (MG-Iα II-1, II-2). MG-Iα II-1 and MG-Iλ II were both freshwater-specific, with MG-Iα II-1 being prevalent in the oxic water and MG-Iλ II in the hypoxic water. Salinity, dissolved oxygen, nutrients and pH were the most important determinants that shaped the differential distribution of MG-I subgroups along Pearl Estuary. Marine Group II Euryarchaeota (MG-II) dominated the saltwater sites, but their abundance was higher in surface waters. The phylogenetic patterns of MG-I subgroups and their habitat preferences provide insight into their phylogeographic relationships. These results highlight the diversification of various ecotypes of archaea, especially of MG-I, under distinct environmental factors in Pearl Estuary, which are of great value for further exploring their ecological functions.
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Qingdao, China.
authors.forename: Jiwen
authors.initials: J
authors.lastname: Liu
authors.forename: Shaolan
authors.initials: S
authors.lastname: Yu
authors.forename: Meixun
authors.initials: M
authors.lastname: Zhao
authors.forename: Biyan
authors.initials: B
authors.lastname: He
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Zhang
mesh_terms: D001105:Archaea / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D044822:Biodiversity; D002681:China; D019641:DNA, Archaeal / Q000235:genetics; D063366:Estuaries; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D054712:Salinity; D012623:Seawater / Q000382:microbiology*
chemical_list: D019641:DNA, Archaeal; D012336:RNA, Ribosomal, 16S
keywords: 16S rRNA gene; 454 pyrosequencing; Marine Group I; Pearl Estuary; habitat preference; hypoxia