Co-occurrence of planktonic bacteria and archaea affects their biogeographic patterns in China’s coastal wetlands

Abstract

Planktonic bacteria and archaea play a key role in maintaining ecological functions in aquatic ecosystems; however, their biogeographic patterns and underlying mechanisms have not been well known in coastal wetlands including multiple types and at a large space scale. Therefore, planktonic bacteria and archaea and related environmental factors were investigated in twenty-one wetlands along China’s coast to understand the above concerns. The results indicated that planktonic bacteria had different biogeographic pattern from planktonic archaea, and both patterns were not dependent on the wetland's types. Deterministic selection shapes the former’s community structure, whereas stochastic processes regulate the latter’s, being consistent with the fact that planktonic archaea have a larger niche breadth than planktonic bacteria. Planktonic bacteria and archaea co-occur, and their co-occurrence rather than salinity is more important in shaping their community structure although salinity is found to be a main environmental deterministic factor in the coastal wetland waters. This study highlights the role of planktonic bacteria-archaea co-occurrence on their biogeographic patterns, and thus provides a new insight into studying underlying mechanisms of microbial biogeography in coastal wetlands.

Co-Occurrence Relationship and Stochastic Processes Affect Sedimentary Archaeal and Bacterial Community Assembly in Estuarine–Coastal Margins

“…Numerous previous studies have explored the co-occurrence of archaea and bacteria in the same habitat and their functional interdependencies [ 22 , 62 ]. However, network analysis found that the coexistence of archaea–archaea and bacteria–bacteria increased with the salinity gradient in estuarine–coastal margins, rather than archaea–bacteria coexistence ( Figure 4 ).…”

“…Stochastic processes correspond to neutral theories and include ecological drift, probabilistic dispersal, and random speciation and extinction. Stochasticity exerts a stronger effect than determinism on the assembly of planktonic archaeal community in coastal wetlands [ 22 ], and bacterial [ 23 ] and archaeal [ 24 ] communities in coastal seawater. However, it is unclear whether stochastic processes dominate the assembly of microbial communities in the estuarine–coastal sediments.…”

Archaeal contribution to carbon-functional composition and abundance in China’s coastal wetlands: Not to be underestimated

“…Bioinformatic analysis of amplicon sequencing and detailed protocols of HT-qPCR QMEC were performed as described in S1. The sequences reported in this study have been deposited in NCBI SRA database with the BioProject numbers PRJNA681135 and PRJNA674461 ( Wang B. L. et al, 2021 ). Shannon index and niche breadth of microbes and carbon-functional genes were conducted with the “vegan_2.6-2” and “spaa_0.2.2” package, respectively.…”

“…Correlation-based network analysis was used for microbes and carbon-functional gene interactions ( Zhu et al, 2017 ; Wang B. L. et al, 2021 ). Co-occurrence networks were constructed using WGCNA libraries in R 3.6.3 and visualized with Gephi 0.9.2 software.…”

“…The functional genes carried by microbes theoretically vary with microbial composition and abundance, but functional redundancy usually makes functional composition more stable than does microbial community in the same habitat ( Chen et al, 2022 ). Microbial community assembly was discerned by niche theory and neutral theory ( Zhang et al, 2022 ), which have found that the relative importance of deterministic factors (abiotic and biotic factors) and stochastic processes (birth, death, speciation, limited dispersal and immigration) depends on regional and local environmental conditions ( Zhou and Ning, 2017 ; Wang B. L. et al, 2021 ). To the best of our knowledge, the assembly process of carbon-functional structure is largely unknown, but a functional gene matrix can form a special microbiome involved in the element cycle and has been regarded as a community based on function rather than on taxonomic groups ( Dong et al, 2021 ; Zhou et al, 2021 ).…”