摘要

       叶际包含各种微生物，这些微生物可能含有多种抗生素抗性基因 (ARG)。然而，我们对抗生素抗性组的组成以及影响叶际ARGs多样性和丰度的因素知之甚少。本研究采用16S rRNA基因扩增子测序和高通量定量PCR方法研究长期（10年以上）有机施肥对叶际细菌群落和抗生素抗性组的影响。 Proteobacteria、Bacteroidetes、Actinobacteria 和 Firmicutes 在叶际细菌群落中占主导地位。长期施用污水污泥和鸡粪改变了叶际细菌群落组成，细菌α多样性显着降低。在叶际中总共检测到 124 个独特的 ARG。污水污泥和鸡粪的施用显着增加了ARGs的丰度，最大富集2638倍。变异分区分析 (VPA) 和网络分析表明 ARGs 的分布与细菌群落组成密切相关。这些结果提高了对植物相关抗生素抗性组多样性和影响 ARGs 在叶际中分布的因素的认识。

       Phyllosphere contains various microorganisms that may harbor diverse antibiotic resistance genes (ARGs). However, we know little about the composition of antibiotic resistome and the factors influencing the diversity and abundance of ARGs in the phyllosphere. In this study, 16S rRNA gene amplicon sequencing and high-throughput quantitative PCR approaches were employed to investigate the effects of long-term (over 10 years) organic fertilization on the phyllosphere bacterial communities and antibiotic resistome. Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes dominated in the phyllosphere bacterial communities. Long-term application of sewage sludge and chicken manure altered the phyllosphere bacterial community composition, with a remarkable decrease in bacterial alpha-diversity. A total of 124 unique ARGs were detected in the phyllosphere. The application of sewage sludge and chicken manure significantly increased the abundance of ARGs, with a maximum 2638-fold enrichment. Variation partitioning analysis (VPA) together with network analysis indicated that the profile of ARGs is strongly correlated with bacterial community compositions. These results improve the knowledge about the diversity of plant-associated antibiotic resistome and factors influencing the profile of ARGs in the phyllosphere.

https://www.sciencedirect.com/science/article/abs/pii/S0048969718327542