Essentiality of nickel and homeostatic mechanisms for its regulation in terrestrial organisms

Abstract

Nickel (Ni) is a naturally occurring element with many industrial uses, including in stainless steel, electroplating, pigments, and ceramics. Consequently, Ni may enter the environment from anthropogenic sources, resulting in locally elevated concentrations in soils. However, Ni is a minor essential element, and, therefore, biota have established systems that maintain Ni homeostasis. This paper discusses the role of Ni as an essential element and reviews storage, uptake, and transport systems used to maintain homeostasis within terrestrial biota. The bioaccumulation and distribution of metals in these organisms are also addressed. In all cases, information on Ni essentiality is very limited compared to other essential metals. However, the available data indicate that Ni behaves in a similar manner to other metals. Therefore, inferences specific to Ni may be made from an understanding of metal homeostasis in general. Nevertheless, it is evident that tissue and organ Ni concentrations and requirements vary considerably within and between species, and metal accumulation in various tissues within a single organism differs as well. High rates of Ni deposition around smelters indicate that Ni in acidic soils may reach concentrations that are toxic to plants and soil decomposers. However, with the exception of hyperaccumulator plants, Ni does not biomagnify in the terrestrial food web, suggesting that toxicity to higher trophic levels is unlikely.

Micro-PIXE studies of elemental distribution in sap-feeding insects associated with Ni hyperaccumulator, Berkheya coddii

“…Data on Ni essentiality in insects are very limited in comparison with other micronutrients. On the other hand, broad spectrum of toxicity, transport, and interactions with other metals has been well documented (Phipps et al 2002). We showed that sap feeders had much lower Ni contents than the appropriate parts of their host plant ( Ni 100 lg g -1 ; K 2.5 wt.%; Ca 0.2 wt.%; Zn 500 lg g -1 ; Fe 500 lg g -1 .…”

Metabolic responses of the isopod Porcellionides pruinosus to nickel exposure assessed by 1H NMR metabolomics

“…However, due to its high usage in industry and the involuntary anthropogenic release, this metal can reach high concentrations in soils [20], potentially disturbing the ecosystems' homeostasis. In previous studies using cell lines [21],d a p h n i d s [22] or fish [23],N i toxicity has been related to oxidative stress, a process commonly induced by metals, which reflects the imbalance between the production of reactive pro-oxidant species and the ability to neutralize their harmful effects.…”

“…Regarding Ni effects on soil invertebrates, the information available is still very scarce, being focused on bioaccumulation and mortality testing (e.g. [20,25]). Recently, our group has addressed the response of terrestrial isopods to long-term Ni exposure by measuring changes in energy reserves and the activity of detoxification enzymes [12].…”

Biogeochemistry of Nickel and Its Release into the Environment

“…Therefore, the presence of Ni hyperaccumulating plants appears to enhance the transfer of Ni from soil to herbivore and carnivore trophic levels. However, with the exception of hyperaccumulator plants, Ni does not biomagnify in the terrestrial foodweb [99], thereby its toxicity to higher trophic levels appears to be unlikely.…”