Relationships between carboxylate-based nutrient-acquisition strategies, phosphorus-nutritional status and rare earth element accumulation in plants

• Published in: Plant and soil 2023-08, Vol.489 (1-2), p.645-666
• Main Authors: Wiche, Oliver, Dittrich, Christine, Pourret, Olivier, Monei, Nthati, Heim, Juliane, Lambers, Hans
• Format: Article
• Language: English
• Subjects: Accumulation; Acidification; Agriculture; Aluminum; Analysis; Availability; Biomedical and Life Sciences; Brassica; Cadmium; Carboxylates; Carboxylic acids; Ecology; Gadolinium; Identification and classification; Life Sciences; Nutrient status; Nutrients; Nutritional status; Phosphorus; Plant growth; Plant Physiology; Plant Sciences; Plant species; Plants; Plants (botany); Rare earth elements; Rare earth metals; Research Article; Rhizosphere; Soil Science & Conservation; Species; Wheat
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-023-06049-9

Background and aims We explored how phosphorus (P) availability influences accumulation of rare earth elements (REE) in plant species with different P-acquisition strategies beyond the commonly explored REE-phosphate precipitation. Methods Two P-efficient carboxylate-releasing lupin species ( Lupinus albus , and L. cosentinii ) and four species with less carboxylate release under P-deficiency ( Triticum aestivum , Brassica napus , Pisum sativum , Cicer arietinum ), were cultivated with a split-root system on two sand types. Phosphorus availability was controlled on one root side by watering the plants with 100 μM P or 0 μM P solutions. Carboxylate release and changes in pH were measured on both sides. Concentrations of nutrients, cadmium (Cd), aluminum (Al), light REE (LREE: La–Eu), and heavy REE (HREE: Gd–Lu, including Y) in roots and shoots were analyzed by ICP-MS. Results P-deficient T. aestivum , B. napus and C. arietinum did not respond with elevated carboxylate release. These species accumulated more REE when the P supply was low and higher REE concentrations were proportional to declining plant growth. However, P. sativum , L. albus and L. cosentinii accumulated less REE when P supply was low. Plants that strongly acidified the rhizosphere and released low quantities of dicarboxylates accumulated more REE (with higher LREE/HREE ratios) than species that released tricarboxylates. Conclusion Our findings suggest that REE accumulation strongly depended on rhizosphere acidification, in concert with the amount and composition of carboxylates determining the exclusion of REE-carboxylate complexes. Leaf REE signatures may offer a promising ionomics screening tool for carboxylate release into the rhizosphere.