Exploring plant nutrient acquisition traits plasticity in response to PFOA stress in crop species: the case of pea, rapeseed and wheat

Perfluorooctanoate (PFOA) contamination in agricultural soils raises increasing concern due to its persistence and phytotoxicity. While prior research has focused on soil physicochemical and biological properties influencing PFOA behavior, less is known about its effects on plant-mediated processes at the root–soil interface—key to nutrient acquisition and rhizosphere dynamics.

In this study, we investigated how two concentrations of PFOA (0.04 and 500 mg kg⁻¹) affect root traits, nutrient uptake, and rhizosphere microbial activity in three crop species—wheat, rapeseed, and pea—grown under controlled greenhouse conditions. After eight weeks, plant biomass and photosynthesis were mostly unaffected at the low concentration but impaired at 500 mg kg⁻¹, especially in rapeseed. Antioxidant responses varied across species, with rapeseed being the most sensitive and pea the most tolerant.

PFOA exposure reduced nodule density in pea and stimulated root exudation of carboxylates such as malate and citrate in all species. These changes coincided with altered shoot elemental composition, notably elevated iron in wheat and manganese in rapeseed and pea. Rhizosphere microbial activity related to carbon metabolism also shifted significantly, in wheat, which released the highest levels of organic acids.

Our findings show that PFOA can strongly alter below-ground plant strategies, with species-specific impacts on nutrient acquisition and rhizosphere interactions. This work underscores the role of root functional traits as early and sensitive indicators of plant responses to soil pollutants. It contributes to a mechanistic understanding of how emerging contaminants like PFOA affect rhizosphere processes relevant to soil health, nutrient cycling, and crop resilience.