The uptake mechanism, translocation,
and subcellular distribution
of azoxystrobin (5 mg kg–1) in wheat plants was
investigated under laboratory conditions. The wheat–water system
reached equilibrium after 96 h. Azoxystrobin concentrations in roots
were much higher than those in stems and leaves under different exposure
times. Azoxystrobin uptake by roots was highly linear at different
exposure concentrations, while the bioconcentration factors and translocation
factors were independent of the exposed concentration at the equilibrium
state. Dead roots adsorbed a larger amount of azoxystrobin than fresh
roots, which was measured at different concentrations. Azoxystrobin
preferentially accumulated in organelles, and the highest distribution
proportion was detected in the soluble cell fractions. This study
elucidated that the passive transport and apoplastic pathway dominated
the uptake of azoxystrobin by wheat roots. Azoxystrobin primarily
accumulated in roots and could be acropetally translocated, but its
translocation capacity from roots to stems was limited. Additionally,
the uptake and distribution of azoxystrobin by wheat plants could
be predicted well by a partition-limited model.