Microbial siderophores and root exudates enhanced goethite dissolution and Fe/As uptake by As-hyperaccumulator Pteris vittata
Autor: | Jing–Wei Fu, Yue Cao, Evandro B. da Silva, Xue Liu, Lena Q. Ma, Bala Rathinasabapathi, Xiao–Xia Shi, Yanshan Chen |
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Rok vydání: | 2017 |
Předmět: |
Siderophore
Goethite Health Toxicology and Mutagenesis Inorganic chemistry Siderophores chemistry.chemical_element 010501 environmental sciences Toxicology Plant Roots 01 natural sciences Arsenicals Soil chemistry.chemical_compound Soil Pollutants Hyperaccumulator Arsenic 0105 earth and related environmental sciences Minerals Rhizosphere biology Chemistry Arsenate Pteris 04 agricultural and veterinary sciences General Medicine biology.organism_classification Pollution Phytoremediation Biodegradation Environmental Solubility visual_art Environmental chemistry Pteris vittata 040103 agronomy & agriculture visual_art.visual_art_medium 0401 agriculture forestry and fisheries Iron Compounds |
Zdroj: | Environmental Pollution. 223:230-237 |
ISSN: | 0269-7491 |
Popis: | Arsenic (As) in soils is often adsorbed on Fe-(hydro)oxides surface, rendering them more resistant to dissolution, which is undesirable for phytoremediation of As-contaminated soils. Arsenic hyperaccumulator Pteris vittata prefers to grow in calcareous soils where available Fe and As are low. To elucidate its mechanisms of acquiring Fe and As from insoluble sources in soils, we investigated dissolution of goethite with pre-adsorbed arsenate (AsV; As-goethite) in presence of four organic ligands, including two root exudates (oxalate and phytate, dominant in P. vittata) and two microbial siderophores (PG12-siderophore and desferrioxamine B). Their presence increased As solubilization from As-goethite from 0.03 to 0.27–5.33 mg L−1 compared to the control. The siderophore/phytate bi-ligand treatment released 7.42 mg L−1 soluble Fe, which was 1.2-fold that of the sum of siderophore and phytate, showing a synergy in promoting As-goethite dissolution. In the ligand-mineral-plant system, siderophore/phytate was most effective in releasing As and Fe from As-goethite. Moreover, the continuous plant uptake induced more As-goethite dissolution. The continued release of As and Fe significantly enhanced their plant uptake (from 0.01 to 0.43 mg plant−1 As and 2.7–14.8 mg plant−1 Fe) and plant growth (from 1.2 to 3.1 g plant−1 fw) in P. vittata. Since microbial siderophores and root exudates often coexist in soil rhizosphere, their synergy in enhancing dissolution of insoluble As-Fe minerals may play an important role in efficient phytoremediation of As-contaminated soils. |
Databáze: | OpenAIRE |
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