Naphthoquinones as allelochemical triggers of programmed cell death

Juglone and plumbagin are plant bioactive derivatives of 1,4-naphthoquinone occurring in plants, whereas lots of these plants belong to invasive species. Clarifying of action of juglone and plumbagin applied on plant cell model represented by tobacco BY-2 cells was the basic aim of this work. It was shown that naphthoquinones are able to induce various structural, functional and enzymatic changes leading to processes of apoptic-like cell death. Using dihydroethidium as fluorescent probe the mechanism of naphthoquinones action was explained. They are able to generate reactive oxygen species, which play important role in processes of programmed cell death. Disruption of mitochondrial respiratory chain was detected too. This study shown that mechanism of naphthoquinones action to plant cells is very complex and predestine them to be very effective compounds in plant competition fight. (C) 2008 Elsevier B.V. All rights reserved