Li Ran, Hu Chen, Wang Jianning, Sun Jun, Wang Ying, Jiao Nianzhi, Xu Dapeng
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen 361102, China.
Microorganisms. 2021 Feb 10;9(2):351. doi: 10.3390/microorganisms9020351.
Marine protists are essential for globally critical biological processes, including the biogeochemical cycles of matter and energy. However, compared with their prokaryotic counterpart, it remains largely unclear how environmental factors determine the diversity and distribution of the active protistan communities on the regional scale. In the present study, the biodiversity, community composition, and potential drivers of the total, abundant, and rare protistan groups were studied using high throughput sequencing on the V9 hyper-variable regions of the small subunit ribosomal RNA (SSU rRNA) along an estuary to basin transect in the northern South China Sea. Overall, Bacillariophyta and Cercozoa were abundant in the surface water; heterotrophic protists including Spirotrichea and marine stramenopiles 3 (MAST-3) were more abundant in the subsurface waters near the heavily urbanized Pearl River estuary; Chlorophyta and Pelagophyceae were abundant at the deep chlorophyll maximum depth, while Hacrobia, Radiolaria, and Excavata were the abundant groups in the deep water. Salinity, followed by water depth, temperature, and other biological factors, were the primary factors controlling the distinct vertical and horizontal distribution of the total and abundant protists. Rare taxa were driven by water depth, followed by temperature, salinity, and the concentrations of PO. The active protistan communities were mainly driven by dispersal limitation, followed by drift and other ecological processes.
海洋原生生物对于全球关键生物过程至关重要，包括物质和能量的生物地球化学循环。然而，与原核生物相比，在区域尺度上环境因素如何决定活跃原生生物群落的多样性和分布在很大程度上仍不清楚。在本研究中，利用高通量测序技术对南海北部从河口到盆地断面的小亚基核糖体RNA（SSU rRNA）的V9高变区进行分析，研究了总原生生物类群、优势原生生物类群和稀有原生生物类群的生物多样性、群落组成及其潜在驱动因素。总体而言，硅藻门和丝足虫纲在表层水中含量丰富；包括旋毛纲和海洋不等鞭毛类3（MAST-3）在内的异养原生生物在高度城市化的珠江口附近的次表层水中更为丰富；绿藻门和褐藻纲在叶绿素最大深度处含量丰富，而囊泡虫类、放射虫类和盘蜷类是深水中的优势类群。盐度，其次是水深、温度和其他生物因素，是控制总原生生物类群和优势原生生物类群明显垂直和水平分布的主要因素。稀有类群受水深驱动，其次是温度、盐度和磷酸盐浓度。活跃的原生生物群落主要受扩散限制驱动，其次是漂流和其他生态过程。
