Interacting effects of heavy metals and ultraviolet radiation on the aquatic macrophyte Elodea nuttallii

• Research unit: COST
• Project number: C11.0117

Key words (English)

UV radiation; mercury; aquatic environment; ma-crophytes; cross-effects; tolerance

Research programs (English)

COST-Action FA0906 - UV-B radiation: A specific regulator of plant growth and food quality in a changing climate (acronym: UV4growth)

Short description (English)

The aim of this study is to determine how the predicted environmental changes of the 21st century will affect aquatic ma-crophytes: namely increased UV radiation combined with heavy metal pollution. We hypothesize that UV and heavy metal stress have interacting effects on the macrophytes and might induce a phenomenon termed cross-tolerance. In the present project, Elodea nuttallii will be exposed to different levels of UV radiation and heavy metal concentration under standardized conditions. Parameters indicating the plant fitness such as growth, pigment content and markers of oxidative stress will be measured. A transcriptomic approach will be employed in order to unravel tolerance mechanisms and stress response on the gene level.

Partners and International Organizations (English)

AT; BE; CZ; DK; EE; FI; FR; DE; EL; HU; IE; IL; IT; LT; NL; NO; PL; PT; RS; SI; ES; SE; TR; UK; UA; NZ

Abstract (English)

The aim of this study was to determine how the predicted environmental changes of the 21st century will affect aquatic macrophytes: namely increased UV radiation combined with metal pollution. We hypothesize that UV and toxic metal stress have interacting effects on the macrophytes and might induce a phenomenon termed cross-tolerance. Single or combined UV and Hg exposure of Elodea nuttallii resulted in oxidative stress in particular when doses increased. In combined exposure we observed additive effect for lipid peroxidation, but antagonist effect for oxidative stress enzymes. We further observed that UV reduced Hg uptake in combined exposure. Transcriptome analysis suggested that amino acids, sulfate and nitrate transporter are involved in Hg accumulation. In addition glutathione pool seems to be central for Hg tolerance in this plant. Combined UV and Hg exposure had also a synergistic effect for up-regulated genes, whereas for down-regulated genes additional UV exposure had an antagonist effect. Globally combined exposure resulted in a smaller stress than additivity hypothesis would predict supporting the hypothesis of some level of cross-tolerance, but did still trigger a significant stress level for the exposed organism.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C11.0117