Phosphorus forms affect the hyphosphere bacterial community involved in soil organic phosphorus turnover

• Published in: Mycorrhiza 2019-07, Vol.29 (4), p.351-362
• Main Authors: Wang, Fei, Kertesz, Michael A., Feng, Gu
• Format: Article
• Language: English
• Subjects: Agriculture; Alkaline phosphatase; Arbuscular mycorrhizas; Bacteria; Biogeochemical cycles; Biomedical and Life Sciences; Communities; Community involvement; Community structure; Ecology; Forestry; Fungi; Hyphae; Life Sciences; Microbiology; Microbiomes; Mineralization; Next-generation sequencing; Organic phosphorus; Organic soils; Original Article; Phosphorus; Phytase; Plant growth; Plant Sciences; Potassium phosphate; Potassium phosphates; Pseudomonas; Relative abundance; Soil microorganisms; Soils
• ISSN: 0940-6360; 1432-1890
• DOI: 10.1007/s00572-019-00896-0

Interactions between bacteria and arbuscular mycorrhizal (AM) fungi play a significant role in mediating organic phosphorus (P) transformations and turnover in soil. The bacterial community in soil is largely responsible for mobilization of the soil organic P pool, and the released P is taken up by extraradical AM hyphae, which mediate its use for plant growth. However, the functional microbiome involved in organic P mineralization in the hyphosphere remains poorly understood. The aim of this study was to determine how AM hyphae-associated bacterial communities related to P turnover in the hyphosphere of leek ( Allium porrum ) respond to different forms of soil P. Using a compartmented microcosm, leek was grown with the AM fungus Funneliformis mosseae , and the extraradical mycelium of F. mosseae was allowed to grow into a separate hyphal compartment containing either no added P, or P as KH 2 PO 4 or phytin. High-throughput sequencing showed that the alkaline phosphatase (ALP)-harboring bacterial community associated with the AM hyphae was dominated by Sinorhizobium , Bradyrhizobium , Pseudomonas , and Ralstonia and was significantly changed in response to different P treatments, with Pseudomonas showing higher relative abundance in organic P treatments than in control and inorganic P treatments. Pseudomonas was also the major genus harboring the β-propeller phytase (BPP) gene in the hyphosphere, but the BPP-harboring community structure was not affected by the presence of different P forms. These results demonstrate the profound differences in ALP- and BPP-harboring bacterial communities in the hyphosphere at bacterial genus level, providing new insights to link bacteria and biogeochemical P cycling driven in association with mycorrhizal hyphae.