Arsenite phytoextraction and its influence on selected nutritional elements in one-year-old tree species

Abstract

Trees have long been recognized as promising for arsenic phytoremediation, however, the most suitable traits of various tree species are still under examination. Therefore, the aim of the studies was to investigate the uptake and accumulation capabilities of As(III) by one-year-old trees from of species (Acer platanoides L., Betula pendula Roth., Quercus robur L., Ulmus laevis Pall) using hydroponic culture. A further aim was to analyse the influence of As(III) on the content of selected nutritional minerals, such as B, Ca, K, Mg, Na and Si.The highest accumulation of As(III) was detected in A. platanoides (BCF=2.16) and Q. robur (BCF=2.69). In A. platanoides >80% of total As(III) of the whole plant was accumulated in its stem while its TF was 10.8. Q. robur TF was 0.1 and it accumulated As(III) predominantly in its roots – >85% of total As(III) of whole the plant. The high As(III) accumulation capabilities of A. platanoides and its location predominantly in the stem classify this tree species as a hyperaccumulator and a good candidate for As(III) phytoextraction while Q. robur would be more suitable for phytostabilization and eco-restoration.As(III) uptake also caused alteration in the content of nutritional minerals. Decreased levels of B and Si were detected in the roots of most trees exposed to As(III) indicating the competition between these elements in the uptake process. In A. platanoides stems a high accumulation of As(III) resulted in a significant decrease of Si content in all the studied organs, suggesting that As(III) was transported from root to shoot predominantly by Si transporters.As(III) also led to a general alteration in the level of other macronutrients – e.g. an increase in the level of Na and K. The reactions varied between tree species and organs. Hence, As(III) uptake and accumulation results in a deterioration of cation balance and homeostasis, which could be one of the factors affecting the vitality of the examined trees.