Hormetic dose responses induced by lanthanum in plants

Evgenios Agathokleous; Mitsutoshi Kitao; Edward J Calabrese

doi:10.1016/j.envpol.2018.10.007

Hormetic dose responses induced by lanthanum in plants

Environ Pollut. 2019 Jan:244:332-341. doi: 10.1016/j.envpol.2018.10.007. Epub 2018 Oct 8.

Authors

Evgenios Agathokleous¹, Mitsutoshi Kitao², Edward J Calabrese³

Affiliations

¹ Hokkaido Research Center, Forestry and Forest Products Research Institute (FFPRI), Forest Research and Management Organization, 7 Hitsujigaoka, Sapporo, Hokkaido, 062-8516, Japan; Research Faculty of Agriculture, Hokkaido University, Kita 9 Nishi 9, Sapporo, Hokkaido, 060-8589, Japan. Electronic address: globalscience@frontier.hokudai.ac.jp.
² Hokkaido Research Center, Forestry and Forest Products Research Institute (FFPRI), Forest Research and Management Organization, 7 Hitsujigaoka, Sapporo, Hokkaido, 062-8516, Japan.
³ Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.

PMID: 30347380
DOI: 10.1016/j.envpol.2018.10.007

Abstract

Rare earth elements (REEs) have recently received particular attention due to their accumulation in the environment. Such heightened recognition prompted our evaluation of the possible occurrence of La-induced plant hormesis in the peer-reviewed literature. This study revealed 703 La-induced hormetic concentration/dose responses in plants, which were quantitatively and qualitatively assessed. The maximum (MAX) biological response to low La concentrations/doses is commonly below 150% of control response, with a geometric mean of 142% at 56 μM (geometric mean). The geometric mean concentration of the no-observed-adverse-effect-level (NOAEL) was 249 μM. The MAX:NOAEL distance was commonly below 5-fold, with a geometric mean of 4.5-fold. Hormetic concentration/dose responses varied as per the growth substrate pH, number of concentrations/doses below the NOAEL, and time window. These results provide a unique insight into the effects of low doses of La on plant growth, as well as offer means for improving experimental designs to assess low dose effects.

Keywords: Biological plasticity; Dose-response; Hormesis; Lanthanum; Stimulation; Stress.

Publication types

Review

MeSH terms

Hormesis / physiology*
Lanthanum / toxicity*
No-Observed-Adverse-Effect Level
Plant Development / drug effects*
Plants / drug effects*
Research Design
Soil Pollutants / toxicity*

Substances

Soil Pollutants
lanthanum chloride
Lanthanum