Plant-Microbe-Uranium Interactions in Phytoremediation of Uranium Contaminated Soil Using Sunflower.

Microbes play a significant role in the phytoremediation of heavy metal contaminated soil. Sunflower (Helianthus annuus) has been widely recognized as one of the most efficient uranium accumulators for remediation of uranium contaminated soil, however the interactions between plant, microbe and uranium is still little known. In this research, High-throughput sequencing of the 16S ribosomal RNA gene and ITS amplicons was carried out to assess the root rhizosphere and entophytic bacterial and fungal communities of 12-week-old sunflowers grown in control soil and soils artificially contaminated with UO₂, UO₃ and UO₂(NO₃)₂.6H₂O, respectively, at a rate of 100 mg U kg^-1. Apart from uranium concentration in shoots and roots, physical and chemical properties of rhizosphere soil included in pH, uranium fractions, and elemental composition were measured. Effect of different uranium compounds on rhizosphere and entophytic microbiota along with the potential contribution of microbiota in phytoremediation were expected to be further understood that will help to develop a more advanced phytoremediation strategy.