Coupling of leaf elemental traits with root fungal community composition reveals a plant resource acquisition strategy in a desert ecosystem

Purpose Plant-associated microbes enhance nutrient access and stress tolerance of the host species, and therefore, are crucial for plant traits and resource strategies. However, the links between aboveground plant traits and belowground microbes related to plant resource strategies under stressful conditions remain poorly understood. Methods We tested the relationships between leaf traits linked to water (carbon isotopic composition, delta C-13) and nutrient use (elemental concentrations and stoichiometry) with microbial compositions in roots and rhizospheres of two dominant species (Artemisia ordosica and Leymus secalinus) in the Mu Us Desert, northern China. Results L. secalinus exhibited higher Mg and Mn concentrations, N:P ratios, stoichiometric flexibility, and root fungi:bacteria ratios, but lower foliar K and Ca concentrations and delta C-13 values than A. ordosica. The leaf N:P of L. secalinus increased with the root fungi:bacteria ratios, whereas the leaf N:P of A. ordosica decreased with the root fungi:bacteria ratios. The plant elemental levels (P, N, K, Ca, Mn, and delta C-13) of L. secalinus but not A. ordosica were significantly related to their root fungal composition. Additionally, the random forest model identified four key fungal families in predicting leaf elemental traits for both plant species. Conclusion The results suggested tight coupling and coordination between leaf elemental traits and root microbial compositions (especially fungal communities) related to plant resource acquisition strategies. By regulating aboveground and belowground feedback loops through trait flexibility and root microbial compositions, the studied plant species can sustain their resource strategies under stressful environmental conditions.

Automated summary

The study found a close relationship between aboveground plant traits and root microbial compositions, which are related to plant resource acquisition strategies. By regulating aboveground and belowground feedback loops, the studied plant species can sustain their resource strategies under stressful environmental conditions.