Multiple factors drive the abundance and diversity of the diazotrophic community in typical farmland soils of China

• Published in: FEMS microbiology ecology 2019-08, Vol.95 (8), p.1
• Main Authors: Han, Li-Li, Wang, Qing, Shen, Ju-Pei, Di, Hong J, Wang, Jun-Tao, Wei, Wen-Xue, Fang, Yun-Ting, Zhang, Li-Mei, He, Ji-Zheng
• Format: Article
• Language: English
• Subjects: Abundance; Acetylene; Acetylene reduction; Agricultural land; Agriculture; Bradyrhizobium; China; Community composition; Comparative analysis; Ecology; Environmental factors; Farms; Gene sequencing; Gram-Negative Aerobic Bacteria - classification; Gram-Negative Aerobic Bacteria - genetics; Gram-Negative Aerobic Bacteria - metabolism; Gram-Negative Anaerobic Bacteria - classification; Gram-Negative Anaerobic Bacteria - genetics; Gram-Negative Anaerobic Bacteria - metabolism; Identification and classification; Microbiological research; Microbiology; NifH gene; Nitrogen; Nitrogen - analysis; Nitrogen cycle; Nitrogen fixation; Nitrogen Fixation - physiology; Nitrogen-fixing microorganisms; Nitrogenase; Nitrogenation; Oxidoreductases - genetics; Polymerase chain reaction; Soil - chemistry; Soil Microbiology; Soil properties; Soil types; Soils; Symbiosis
• ISSN: 1574-6941; 0168-6496; 1574-6941
• DOI: 10.1093/femsec/fiz113

ABSTRACT Biological nitrogen fixation plays an important role in nitrogen cycling by transferring atmospheric N2 to plant-available N in the soil. However, the diazotrophic activity and distribution in different types of soils remain to be further explored. In this study, 152 upland soils were sampled to examine the diazotrophic abundance, nitrogenase activity, diversity and community composition by quantitative polymerase chain reaction, acetylene reduction assay and the MiSeq sequencing of nifH genes, respectively. The results showed that diazotrophic abundance and nitrogenase activity varied among the three soil types. The diazotrophic community was mainly dominated by Bradyrhizobium, Azospirillum, Myxobacter, Desulfovibrio and Methylobacterium. The symbiotic diazotroph Bradyrhizobium was widely distributed among soils, while the distribution of free-living diazotrophs showed large variation and was greatly affected by multiple factors. Crop type and soil properties directly affected the diazotrophic ɑ-diversity, while soil properties, climatic factors and spatial distance together influenced the diazotrophic community. Network structures were completely different among all three types of soils, with most complex interactions observed in the Red soil. These findings suggest that diazotrophs have various activities and distributions in the three soil types, which played different roles in nitrogen input in agricultural soil in China, being driven by multiple environmental factors. The symbiotic diazotroph Bradyrhizobium was widely distributed in China, while the distribution of free-living diazotrophs was affected by multiple factors, including soil properties, climatic factors and spatial distance.