Work

Aluminum (Al) favors phosphorus (P) nutrition in Al-tolerant Amaranthus cruentus L. under P deficiency

Year: 2026

Type: article

Abstract: Acidic soils are characterized by excess aluminum (Al) and low phosphorus (P) availability. However, the interactive effects of these elements within plants and the rhizosphere remain understudied. Red amaranth ( Amaranthus cruentus L.), an Al-tolerant species, was precultured under sufficient (+ P) and deficient (‒P) phosphorus conditions, followed by treatment with Al for two weeks. A low ionic strength nutrient solution (pH 4.0) for avoiding Al-P precipitation, with an equal free Al 3+ activity (60 µM) in the + P and −P mediums, was employed for plant treatment. Biomass and root elongation data indicated lower susceptibility of + P plants to Al 3+ phytotoxicity compared with –P plants. Enhanced leaf accumulation of betacyanin and higher root exudation of phenolics, accompanied by less Al 3+ binding to the root cell wall, were among the mechanisms for lower susceptibility of + P plants to Al 3+ rhizotoxicity. However, our findings suggest the existence of some adaptive mechanisms acting under a combination of Al 3+ toxicity with P deficiency. Phosphorus-deficient plants exhibited lower leaf Al accumulation, higher Al-induced H + release, and acid phosphatase activity compared to + P plants. In addition, Al treatment enhanced the leaves’ total and free cytosolic inorganic P (Pi) levels and improved the plants ability to mobilize sparingly soluble phosphorus (Ca 3 (PO 4 ) 3 ). Our data suggest that although sufficient P nutrition is necessary for full expression of adaptive mechanisms to Al 3+ toxicity, modifications in the rhizosphere of –P plants mediated by Al 3+ may significantly improve Pi availability and help maintain Pi homeostasis in plants growing on acidic soils.

Source: Discover Plants.

DOI: 10.1007/s44372-025-00407-w

Authors: Fatemeh Nazari, Roghieh Hajiboland, Charlotte Poschenrieder

Institutions: University of Tabriz, Universitat Autònoma de Barcelona

Language: English

Topic: Aluminum toxicity and tolerance in plants and animals

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: diamond

Funders: Generalitat de Catalunya, University of Tabriz