Organic phosphorus levels change the hyphosphere phoD-harboring bacterial community of Funneliformis mosseae

Abstract

The phoD-harboring bacterial community is responsible for organic phosphorus (P) mineralization in soil and is important for understanding the interactions between arbuscular mycorrhizal (AM) fungi and phosphate-solubilizing bacteria (PSB) at the community level for organic P turnover. However, current understanding of the phoD-harboring bacterial community associated with AM fungal hyphae responses to organic P levels remains incomplete. Here, two-compartment microcosms were used to explore the response of the phoD-harboring bacterial community in the hyphosphere to organic P levels by high-throughput sequencing. Extraradical hyphae of Funneliformis mosseae enriched the phoD-harboring bacterial community and organic P levels significantly altered the composition of the phoD-harboring bacterial community in the Funneliformis mosseae hyphosphere. The relative abundance of dominant families Pseudomonadaceae and Burkholderiaceae was significantly different among organic P treatments and were positively correlated with alkaline phosphatase activity and available P concentration in the hyphosphere. Furthermore, phytin addition significantly decreased the abundance of the phoD gene, and the latter was significantly and negatively correlated with available P concentration. These findings not only improve the understanding of how organic P influences the phoD-harboring bacterial community but also provide a new insight into AM fungus-PSB interactions at the community level to drive organic P turnover in soil.

Keywords: phoD-harboring bacterial community; Arbuscular mycorrhizal fungi; Hyphosphere; Organic P levels.