Abk. Jespers et al., INTERFERENCE OF THE PHENYLPYRROLE FUNGICIDE FENPICLONIL WITH MEMBRANES AND MEMBRANE-FUNCTION, Pesticide science, 40(2), 1994, pp. 133-140
The phenylpyrrole fungicide fenpiclonil accumulates to high levels in
mycelium of Fusarium sulphureum and artificial liposomes. The accumula
tion is a result of a physicochemical distribution of the fungicide ov
er lipid-like material of the mycelium and the medium. Accumulation is
reversible, as the fungicide can easily be removed from the mycelium
by washing with water. Fenpicionil is not metabolized by the fungus du
ring incubation for 24 h. The fungicide affects neither membrane fluid
ity in artificial liposomes nor amino acid accumulation in bacterial v
esicles. Thus, accumulation of the fungicide does not seem to affect t
he functioning of membranes. Fenpiclonil induces the accumulation of t
he membrane-potential probe tetraphenylphosphonium bromide by F. sulph
ureum. Since accumulation of this probe probably reflects the cumulati
ve potential over all cell membranes, the increased accumulation is mo
re likely a result of changes of potentials over membranes of intracel
lular organelles rather than plasma membrane hyperpolarization. Hence,
the previously described effects of fenpiclonil on amino acid and sac
charide uptake cannot be explained by plasma membrane hyperpolarizatio
n.