State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China.
Microbiome. 2021 Jan 22;9(1):20. doi: 10.1186/s40168-020-00978-8.
Soil methanogens participate in complex interactions, which determine the community structures and functions. Studies continue to seek the coexistence patterns of soil methanogens, influencing factors and the contribution to methane (CH) production, which are regulated primarily by species interactions, and the functional significance of these interactions. Here, methane emissions were measured in rice paddies across the Asian continent, and the complex interactions involved in coexistence patterns of methanogenic archaeal communities were represented as pairwise links in co-occurrence networks.
The network topological properties, which were positively correlated with mean annual temperature, were the most important predictor of CH emissions among all the biotic and abiotic factors. The methanogenic groups involved in commonly co-occurring links among the 39 local networks contributed most to CH emission (53.3%), much higher than the contribution of methanogenic groups with endemic links (36.8%). The potential keystone taxa, belonging to Methanobacterium, Methanocella, Methanothrix, and Methanosarcina, possessed high linkages with the methane generation functional genes mcrA, fwdB, mtbA, and mtbC. Moreover, the commonly coexisting taxa showed a very different assembly pattern, with ~ 30% determinism and ~ 70% stochasticity. In contrast, a higher proportion of stochasticity (93~99%) characterized the assembly of endemically coexisting taxa.
These results suggest that the coexistence patterns of microbes are closely tied to their functional significance, and the potential importance of common coexistence further imply that complex networks of interactions may contribute more than species diversity to soil functions. Video abstract.
土壤产甲烷菌参与复杂的相互作用，这些相互作用决定了微生物群落的结构和功能。研究人员一直在探索土壤产甲烷菌的共存模式、影响因素及其对甲烷（CH）产生的贡献，这些主要受种间相互作用的调节，以及这些相互作用的功能意义。在这里，测量了亚洲大陆稻田中的甲烷排放量，并将产甲烷古菌群落共存模式中的复杂相互作用表示为共生网络中的成对链接。
网络拓扑特性与年平均温度呈正相关，是所有生物和非生物因素中对 CH 排放最重要的预测因子。在 39 个本地网络中，共同出现的链接所涉及的产甲烷菌群落在 CH 排放中贡献最大（53.3%），远高于特有链接所涉及的产甲烷菌群的贡献（36.8%）。属于 Methanobacterium、Methanocella、Methanothrix 和 Methanosarcina 的潜在关键类群与甲烷生成功能基因 mcrA、fwdB、mtbA 和 mtbC 具有高连接性。此外，共同共存的分类群表现出非常不同的组装模式，确定性约为 30%，随机性约为 70%。相比之下，特有共存分类群的组装具有更高比例的随机性（93%~99%）。
这些结果表明，微生物的共存模式与其功能意义密切相关，共同共存的潜在重要性进一步表明，相互作用的复杂网络可能比物种多样性对土壤功能更重要。视频摘要。
