NiO(s) (bunsenite) is not available to Alyssum species

Abstract

To determine if the Ni-hyperaccumulator Alyssum corsicum can absorb Ni from the kinetically inert crystalline mineral NiO(s) (bunsenite). A. corsicum and A. montanum plants were grown for 30 days in a serpentine Hoagland solution. NiO was provided at 0 or 0.1 g L −1 (1.34 mmol L −1 ) as reagent grade NiO particles <1 μm diameter, continuously mixed by aeration. A. corsicum and A. montanum shoots contained 19.4 and 5.2 mg Ni kg −1 DW with NiO, and 3.0 and 1.1 mg Ni kg −1 DW shoots, respectively in the control treatment. A. corsicum normally absorbs over 12,000 mg Ni kg −1 shoots when supplied 300 μM soluble Ni. Roots were coated with the NiO particles and contained 3-5% Ni at harvest. Despite the small Ni accumulation in the NiO treatment above control, A. corsicum is not capable of dissolving and hyperaccumulating Ni from NiO.

Bioaccumulation, translocation and phytoremediation by endemic serpentinophyte Artemisia alba Turra

“…The Ni as an activator of the enzyme urease allows plants to utilize nitrogen from urea. There are some opinions that as Ni 2+ is absorbed by roots, a diffusion depletion zone is formed in the rhizosphere and Ni 2+ is released from solid or soluble bound forms to maintain soil solution equilibria (FELLET et al, 2009). According to some studies the normal plants and crop species generally contain 1-5 mg Ni kg -1 (BROOKS, 1987;CHANEY et al, 2008.…”

Phytoremediation of Soil Trace Elements

“…NiO was likely a form emitted from the nickel refinery. A basic test of whether Alyssum roots could dissolve this comparatively inert compound showed that Alyssum accumulated negligible Ni during a month of root exposure to 1 mm NiO particles [51]. Phytoextraction cannot deal with NiO or similar kinetically inert metal species.…”