Eo Jinu, Kim Myung-Hyun, Kim Min-Kyeong, Choi Soon-Kun
National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea.
Microorganisms. 2021 Apr 29;9(5):961. doi: 10.3390/microorganisms9050961.
Reducing management intensity according to the topography of pastures can change the dominant plant species from sown forages to weeds. It is unclear how changes in species dominance in plant community drive spatial variation in soil bacterial community characteristics and functions in association with edaphic condition. Analysing separately the effects of both plant communities and soil chemical properties on bacterial community is crucial for understanding the biogeographic process at a small scale. In this paper, we investigated soil bacterial responses in five plant communities (two forage and three weed), where >65% of the coverage was by one or two species. The structure and composition of the bacterial communities in the different microbiome were analysed using sequencing and their characteristics were assessed using the Functional Annotation of Prokaryotic Taxa (FAPROTAX) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Firmicutes and Planctomycetes responded only to one specific plant community, and each plant community harboured unique operational taxonomic units (OTUs) at the species level. There were a large percentage of uniquely absent OTUs for specific plant communities, suggesting that a negative effect is critical in the relationship between plants and bacteria. Bacterial diversity indices were influenced more by soil chemical properties than by plant communities. Some putative functions related to C and N recycling including nitrogen fixation were correlated with pH, electrical conductivity (EC) and nutrient levels, and this also implied that some biological functions, such as ureolysis and carbon metabolism, may decline when fertilisation intensity is reduced. Taken together, these results suggest that a shift of dominant species in plant community exerts individual effects on the bacterial community composition, which is different from the effect of soil chemical properties.
根据牧场地形降低管理强度会使优势植物物种从播种牧草转变为杂草。目前尚不清楚植物群落中物种优势度的变化如何与土壤条件相关联，驱动土壤细菌群落特征和功能的空间变异。分别分析植物群落和土壤化学性质对细菌群落的影响，对于理解小尺度下的生物地理过程至关重要。在本文中，我们调查了五个植物群落（两个牧草群落和三个杂草群落）中的土壤细菌响应，其中超过65%的覆盖率由一两种物种构成。使用测序分析不同微生物群落中细菌群落的结构和组成，并使用原核生物分类群功能注释（FAPROTAX）和京都基因与基因组百科全书（KEGG）途径评估其特征。厚壁菌门和浮霉菌门仅对一个特定植物群落有响应，并且每个植物群落在物种水平上都有独特的可操作分类单元（OTU）。特定植物群落中存在大量独特缺失的OTU，这表明负面影响在植物与细菌的关系中至关重要。细菌多样性指数受土壤化学性质的影响大于受植物群落的影响。一些与碳和氮循环相关的假定功能，包括固氮作用，与pH、电导率（EC）和养分水平相关，这也意味着当施肥强度降低时，一些生物学功能，如尿素分解和碳代谢，可能会下降。综上所述，这些结果表明植物群落中优势物种的转变对细菌群落组成产生个体影响，这与土壤化学性质的影响不同。
