Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China.
Sci Total Environ. 2019 Nov 20;692:769-783. doi: 10.1016/j.scitotenv.2019.07.088. Epub 2019 Jul 7.
Based on the field surveys aimed at understanding the variations of Synechococcus (Syn) abundance in the Pearl River Estuary during different seasons. We found that heavy terrestrial precipitation result in significant riverine runoffs and promote Syn growth, extension and blooms during warm and wet seasons. To understand the ecological role of Syn play in this estuary during wet seasons, we combined flow cytometry and high throughput sequencing (HTS) of 16S rDNA to investigate the phytoplankton distribution patterns and the potential shaping mechanisms during a typical wet season. During the cruise, picophytoplankton, especially Syn, and Nano-eukaryotes contributed importantly to the total phytoplankton biomass of the estuary. Syn can be further divided into phycoerythrin (PE)-rich Syn and phycocyanin (PC)-rich Syn, with PC-rich Syn about 1.5 times higher than PE-rich Syn in abundance. Both PE-rich Syn (60.75 × 10 cells ml) and PC-rich Syn (604.05 × 10 cells ml) reach the highest abundance at the lower part of the estuary. Moreover, PE-rich Syn can be divided into two subgroups which showed different salinity preference, with PE1 distributed in the high salinity area (with salinity >25) while PE2 in the middle salinity area (with salinity 7-20). Our results from the 16S rDNA sequencing also indicated abundant diversity and different niche adaptation of Syn with the operational taxonomic units (OTUs) along the estuary. Besides, analysis also indicated a tight correlation between estuarine Syn and active heterotrophic bacteria, especially groups of Rhodobacteria and Actionobacteria.
基于旨在了解珠江口不同季节中聚球藻（Syn）丰度变化的实地调查，我们发现，强烈的陆地降水导致大量的河流径流入海，并在温暖潮湿的季节促进了 Syn 的生长、扩张和爆发。为了了解 Syn 在这个河口湿地季节中的生态作用，我们结合流式细胞术和高通量 16S rDNA 测序（HTS），研究了典型湿季浮游植物的分布模式和潜在的塑造机制。在考察过程中，微微型浮游植物，特别是 Syn 和纳米真核生物，对河口浮游植物生物量的贡献非常重要。Syn 可进一步分为藻红蛋白（PE）丰富的 Syn 和藻蓝蛋白（PC）丰富的 Syn，PC 丰富的 Syn 的丰度比 PE 丰富的 Syn 高 1.5 倍。PE 丰富的 Syn（60.75×10 个细胞/ml）和 PC 丰富的 Syn（604.05×10 个细胞/ml）在河口下游达到最高丰度。此外，PE 丰富的 Syn 可分为两个亚组，它们对盐度的偏好不同，PE1 分布在高盐区（盐度>25），而 PE2 分布在低盐区（盐度 7-20）。我们对 16S rDNA 测序的结果还表明，Syn 的丰富多样性和不同生态位适应能力沿河口存在差异，其分类单元（OTUs）沿河口分布。此外，分析还表明河口 Syn 与活性异养细菌，特别是红杆菌和行动杆菌组之间存在紧密的相关性。
