La Trobe

Long-term nutrient inputs shift soil microbial functional profiles of phosphorus cycling in diverse agroecosystems

journal contribution
posted on 2021-01-15, 02:18 authored by Z Dai, G Liu, H Chen, C Chen, J Wang, S Ai, D Wei, D Li, B Ma, Caixian TangCaixian Tang, PC Brookes, Jianming Xu
© 2019, The Author(s). Microorganisms play an important role in soil phosphorus (P) cycling and regulation of P availability in agroecosystems. However, the responses of the functional and ecological traits of P-transformation microorganisms to long-term nutrient inputs are largely unknown. This study used metagenomics to investigate changes in the relative abundance of microbial P-transformation genes at four long-term experimental sites that received various inputs of N and P nutrients (up to 39 years). Long-term P input increased microbial P immobilization by decreasing the relative abundance of the P-starvation response gene (phoR) and increasing that of the low-affinity inorganic phosphate transporter gene (pit). This contrasts with previous findings that low-P conditions facilitate P immobilization in culturable microorganisms in short-term studies. In comparison, long-term nitrogen (N) input significantly decreased soil pH, and consequently decreased the relative abundances of total microbial P-solubilizing genes and the abundances of Actinobacteria, Gammaproteobacteria, and Alphaproteobacteria containing genes coding for alkaline phosphatase, and weakened the connection of relevant key genes. This challenges the concept that microbial P-solubilization capacity is mainly regulated by N:P stoichiometry. It is concluded that long-term N inputs decreased microbial P-solubilizing and mineralizing capacity while P inputs favored microbial immobilization via altering the microbial functional profiles, providing a novel insight into the regulation of P cycling in sustainable agroecosystems from a microbial perspective.

History

Publication Date

2020-03-01

Journal

The ISME Journal: multidisciplinary journal of microbial ecology

Volume

14

Issue

3

Pagination

14p. (p. 757-770)

Publisher

Springer Nature

ISSN

1751-7362

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