Soil organic phosphorus is mainly hydrolyzed via phosphatases from ectomycorrhiza-associated bacteria rather than ectomycorrhizal fungi

Microbes play central roles in soil nutrient cycling, yet a limited range of microbial community characteristics have been used to explain ecosystem nutrient cycling rates and their importance relative to plant and abiotic factors remains unclear. In this study, we assessed which of 126 commonly measured soil fungal and bacterial community characteristics best explained soil nitrogen (N) and phosphorus (P) cycling rates in temperate forests in the Northeastern U.S., as well as the relative contributions of microbial, plant, and abiotic factors. Using boosted regression tree modeling, we identified the microbial variables with the highest contributions to models explaining nutrient cycling rates: the relative abundances of ectomycorrhizal fungi and N-decomposition genes from oligotrophic bacteria were the most important for net ammonification, the relative abundances of indicator taxa in bacterial networks, nitrifying bacteria, and copiotrophic bacteria were the most important for net nitrification, and the relative abundance of fungal P-cycling oxidoreductase genes was the most important for net soil phosphate change. Microbial variables explained more variation than plant and abiotic variables in multivariate linear models of net nitrification and net phosphate release rates, but not net ammonification rates, which were largely explained by soil edaphic factors. Leaf litter traits were also important in explaining variation in net nitrification rates, and soil temperature was important in explaining rates of net phosphate release in soil. Collectively, our findings suggest that the N-cycling capacity of microbial functional guilds and fungal community P-cycling capacity should be incorporated into ecosystem biogeochemical models to improve our predictions and understanding of nutrient cycling and related ecological processes.

show abstract

Growing in phosphorus‐impoverished habitats in south‐western Australia: How general are phosphorus‐acquisition and ‐allocation strategies among Proteaceae, Fabaceae and Myrtaceae species?

Shen,

Ranathunge,

de Tombeur

et al. 2024

Plant Cell & Environment

View full text Add to dashboard Cite

Numerous phosphorus (P)‐acquisition and ‐utilisation strategies have evolved in plants growing in severely P‐impoverished environments. Although these strategies have been well characterised for certain taxa, like Proteaceae, P‐poor habitats are characterised by a high biodiversity, and we know little about how species in other families cope with P scarcity. We compared the P‐acquisition and leaf P‐allocation strategies of Fabaceae and Myrtaceae with those of Proteaceae growing in the same severely P‐impoverished habitat. Myrtaceae and Fabaceae exhibited multiple P‐acquisition strategies: P‐mining by carboxylates or phosphatases, P uptake facilitated by carboxylate‐releasing neighbours, and dependence on the elevated soil P availability after fire. Surprisingly, not all species showed high photosynthetic P‐use efficiency (PPUE). Highly P‐efficient species showed positive correlations between PPUE and the proportion of metabolite P (enzyme substrates), and negative correlations between PPUE and phospholipids (cellular membranes) and nucleic acid P (mostly ribosomal RNA), while we found no correlations in less P‐efficient species. Overall, we found that Myrtaceae and Fabaceae used a wider range of strategies than Proteaceae to cope with P scarcity, at both the rhizosphere and leaf level. This knowledge is pivotal to better understand the mechanisms underlying plant survival in severely nutrient‐impoverished biodiverse ecosystems.

show abstract

Soil organic phosphorus is mainly hydrolyzed via phosphatases from ectomycorrhiza-associated bacteria rather than ectomycorrhizal fungi

Cited by 3 publications

References 78 publications

Determine leaf manganese concentration to estimate rhizosheath carboxylates of mycorrhizal plants in forest ecosystems

Determine leaf manganese concentration to estimate rhizosheath carboxylates of mycorrhizal plants in forest ecosystems

Microbial functional guilds and genes are key to explaining soil nutrient cycling alongside soil and plant variables

Growing in phosphorus‐impoverished habitats in south‐western Australia: How general are phosphorus‐acquisition and ‐allocation strategies among Proteaceae, Fabaceae and Myrtaceae species?

Contact Info

Product

Resources

About