Effect of Short-Term Phosphorus Supply on Rhizosphere Microbial Community of Tea Plants

Abstract

Microbes play an important role in rhizosphere phosphorus (P) activation and root P absorption in low P-available soils. However, the responses of the rhizosphere microbial community to P input and its effects on P uptake by tea plants have not been widely reported. In this study, the high-throughput sequencing of the 16S rRNA gene and the ITS2 region was employed to examine the responses of tea rhizosphere microbiomes to different P input rates (low-P, P0: 0 mg·kg−1 P; moderate-P, P1: 87.3 mg·kg−1 P; high-P, P2: 436.5 mg·kg−1 P). The results showed that the P input treatments significantly reduced the soil C: N ratio and C: P ratio compared to the P0 treatment (p p Proteobacteria, Actinobacteria and Acidobacteria, while in the fungal community they were Ascomycota and Mortierellomycota. In addition, P input enriched the relative abundance of Actinobacteria and Proteobacteria but decreased the relative abundance of Acidobacteria. The Mantel correlation analysis showed that the fungal community was influenced by P input, whereas bacterial community was affected by the soil TC and C: N ratio. Furthermore, the P input treatments enhanced the TCA cycle, amino and nucleotide glucose metabolism, starch and sucrose metabolism, and phosphotransferase system expression, which could promote C and N cycling. On the contrary, the P input treatments negatively affected the growth of arbuscular mycorrhizal fungi. The PLS-PM model revealed that the rhizosphere bacterial and fungal communities, respectively, negatively and positively affected the P content by affecting the biomass. Meanwhile, rhizosphere microbial function profiles affected the P content of tea plants directly and positively. In summary, moderate P input favors the rhizosphere microbial diversity and functions in the short-term pot experiment. Therefore, we suggest that moderate P input should be recommended in practical tea production, and a further field test is required.

Keywords

• P input
• acidic soils
• rhizosphere microbial
• microbial function
• tea plants