Phosphorus Stress-Induced Changes in Plant Root Exudation Could Potentially Facilitate Uranium Mobilization from Stable Mineral Forms

Abstract

Apparent deficiency of soil mineral nutrients often triggers specific physio-morphological changes in plants, and some of these changes could also inadvertently increase the ability of plants to mobilize radionuclides from stable mineral forms. This work, through a series of sand-culture, hydroponics, and batch-equilibration experiments, investigated the differential ability of root exudates of Andropogon virginicus grown under conditions with variable phosphorus (P) availability (KHPO, FePO, Ca(PO), and no P) to solubilize uranium (U) from the uranyl phosphate mineral Chernikovite. The mineral form of P, and hence the bioavailability of P, affected the overall composition of the root exudates. The lower bioavailable forms of P (FePO and Ca(PO)), but not the complete absence of P, resulted in a higher abundance of root metabolites with chelating capacity at 72 hrs after treatment application. In treatments with lower P-bioavailability, the physiological amino acid concentration inside of the roots increased, whereas the concentration of organic acids in the roots decreased due to the active exudation. In batch dissolution experiments, the organic acids, but not amino acids, increase the dissolution U from Chernikovite. The root exudate matrix of plants exposed to low available forms of P induced a >60% increase in U dissolution from Chernikovite due to 5-16 times greater abundance of organic acids in these treatments. However, this was ca. 70% of the theoretical dissolution achievable by this exudate matrix. These results highlight the potential of using active management of soil P as an effective tool to alter the plant-mediated mobilization of U in contaminated soil.

Plant species-dependent transformation and translocation of ceria nanoparticles

“…Phosphate deficiency can induce a high abundance of metabolites with chelating ability and increase the active exudation of organic acids out from the roots. 23 This process will enhance the dissolution of nCeO 2 . We further calculated the absolute contents of CeIJIV) and CeIJIII) in the roots and shoots by multiplying their proportion by the total Ce contents (Table S4 †).…”

Effect of phosphorus supply on root traits of two Brassica oleracea L. genotypes

“…Efficient soybean genotypes, for example, respond to low P availability by exuding a greater quantity of organic compounds into the rhizosphere, which increases P availability and results in the crop meeting P requirements, producing consistent biomass and seed yield with reduced fertiliser addition [18]. Furthermore, the (bio) availability of P i can affect the overall profile of the root exudates [19]. In P-deficient strawberry (Fragaria × ananassa cv.…”

“…Phosphorus-deficiency in plants can also affect the uptake of other essential and non-essential mineral elements [19,21]. In particular, P deficiency can induce zinc (Zn) over-accumulation [22][23][24][25].…”

Crop root Exudate Composition‐Dependent Disassembly of Lignin‐Fe‐Hydroxyapatite Supramolecular Structures: A Better Rhizosphere Sensing Platform for Smart Fertilizer Development

“…[9] Additionally, stress-induced changes in plant physiology are known to affect exudate composition (e.g., variations in organic acid composition). [10][11][12] Therefore, an advanced sensing platform capable of differentiating crop stress states and the presence of plant roots could be developed based on crop state-driven exudate variations. As mentioned above, such a fertilizer should ideally be made with non-toxic and lowcost materials to allow for bulk manufacturing and minimize human health risks.…”