Phytomanagement of a Lead-Polluted Shooting Range Using an Aromatic Plant Species and Its Effects on the Rhizosphere Bacterial Diversity and Essential Oil Production

This field study aimed to assess the baseline conditions of a long-term shooting range in Argentina polluted with 428 mg kg(-1) lead (Pb) to evaluate the establishment and development of Helianthus petiolaris plants and address the efficacy of the phytomanagement strategy through: (i) element accumulation in plant tissues; (ii) rhizosphere bacterial diversity changes by Illumina Miseq (TM), and (iii) floral water and essential oil yield, composition, and element concentration by GC-MS and ICP. After one life cycle growing in the polluted sites, in the roots of Helianthus petiolaris plants, Pb concentration was between 195 and 304 mg kg(-1) Pb. Only a limited fraction of the Pb was translocated to the aerial parts. The predominance of the genus Serratia in the rhizosphere of Helianthus petiolaris plants cultivated in the polluted sites and the decrease in the essential oil yield were some effects significantly associated with soil Pb concentration. No detectable Pb concentration was found in the floral water and essential oil obtained. Extractable Pb concentration in the soil reduced between 28% and 45% after the harvest. This work was supported by the Ibero-American Development Bank under grant FONTAGRO (ATN/RF-16110-RG), Pluriannuals Projects of Investigation-CONICET (PIP0730), and the Centre for Environmental Sciences of Hasselt University, Belgium, under grant BOF-BILA No. 8546. Thanks to Andrea R. Costantino and Natalia Lazzarini from the Instituto Química del Sur, Bahía Blanca, Bs As, Argentina, for their collaboration on the GC–MS analysis of the essential oils.