Stimulating and toxic effects of graphene oxide on Betula pubescens microclones

Abstract

We have studied the impact of graphene oxide (GO) at 1.5 – 15 μg/L on Betula pubescens microclones. Discovered, that the nanomaterial protects the plants against phytopathogens at the stage of culture establishment and promotes a 25% increase in the shoots survival rate. Further growth stimulation was observed in the groups treated with 1.5 and 3 μg/L, where the shoots length increased by 1.8 and 1 cm, and the number of leaves increased by 2 and 1.5 times respectively. 15 μg/L reduced the height of shoots by 20%. At the multiplication stage addition of GO enhanced the plantlets survival rate by 20% and had a stimulating effect on the birch regenerants growth, as well as on the number of leaves. The data on the plantlets survival rate and their morphometric analysis results correspond well with the biochemical assessment, namely in the GO group both photosynthetic and catalase activity exceeded those of the control group by 2 and 1.5 times, respectively. At the same time, histological analysis exhibits reduced number of stomata in the GO-treated group. At the rooting stage addition of 1.5 μg/L GO to the growth medium increased the number of plantlets with roots by 10% compared to control.