Shi Lei, Xia Pinhua, Lin Tao, Li Guoqing, Wang Tianyou, Du Xin
Guizhou Province Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, No. 116 Baoshan Road (N), Guiyang, 550001, Guizhou, China.
Microb Ecol. 2023 Jan;85(1):87-99. doi: 10.1007/s00248-021-01956-9. Epub 2022 Jan 7.
In shallow macrophytic lakes, epiphytic biofilms are formed on the surface of submerged plant stems and leaves because of algae and bacterial accumulation. Epiphytic biofilms significantly impact the health of the host vegetation and the biogeochemical cycling of lake elements. However, community diversity, species interactions, and community assembly mechanisms in epiphytic bacterial communities (EBCs) of plants during different growth periods are not well understood. We investigated the successional dynamics, co-occurrence patterns, and community assembly processes of epiphytic biofilm bacterial communities of submerged plants, Najas marina and Potamogeton lucens, from July to November 2020. The results showed a significant seasonal variation in EBC diversity and richness. Community diversity and richness increased from July to November, and the temperature was the most important driving factor for predicting seasonal changes in EBC community structure. Co-occurrence network analysis revealed that the average degree and graph density of the network increased from July to November, indicating that the complexity of the EBC network increased. The bacterial community co-occurrence network was limited by temperature, pH, and transparency. The phylogeny-based null model analysis showed that deterministic processes dominated the microbial community assembly in different periods, increasing their contribution. In addition, we found that as the dominance of deterministic processes increased, the microbial co-occurrence links increased, and the potential interrelationships between species became stronger. Thus, the findings provide insights into the seasonal variability of EBC assemblage and co-occurrence patterns in lacustrine ecosystems.
在浅水大型植物湖泊中，由于藻类和细菌的积累，附生生物膜会在沉水植物的茎和叶表面形成。附生生物膜对宿主植被的健康以及湖泊元素的生物地球化学循环有显著影响。然而，不同生长时期植物附生细菌群落（EBC）的群落多样性、物种相互作用和群落组装机制尚不清楚。我们于2020年7月至11月调查了沉水植物小茨藻和光叶眼子菜附生生物膜细菌群落的演替动态、共现模式和群落组装过程。结果表明，EBC的多样性和丰富度存在显著的季节变化。群落多样性和丰富度从7月到11月增加，温度是预测EBC群落结构季节变化的最重要驱动因素。共现网络分析表明，网络的平均度和图密度从7月到11月增加，表明EBC网络的复杂性增加。细菌群落共现网络受温度、pH值和透明度的限制。基于系统发育的零模型分析表明，确定性过程在不同时期主导了微生物群落的组装，并增加了它们的贡献。此外，我们发现随着确定性过程的主导地位增加，微生物共现联系增加，物种之间的潜在相互关系变得更强。因此，这些发现为湖泊生态系统中EBC组装和共现模式的季节变异性提供了见解。
