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Physiological Factors Affecting Uptake and Translocation of Glufosinate
journal contribution
posted on 2020-02-25, 19:36 authored by Hudson K. Takano, Roland Beffa, Christopher Preston, Philip Westra, Franck E. DayanGlufosinate
is considered a contact herbicide because of its fast
activity and limited translocation in plants. We used Palmer amaranth
(Amaranthus palmeri S. Watson) as a
model species to study plant-related factors affecting glufosinate
uptake and translocation. Glufosinate uptake increased rapidly during
the initial 24 h, achieving maximum uptake from this time on. The
rate of uptake saturated with doses higher than 250 μM glufosinate,
suggesting the involvement of a membrane transporter. When glufosinate
concentrations were higher (>1 mM), uptake was a simple diffusion
process in favor of a concentration gradient between the inside and
the outside of the cells. Glufosinate uptake was inhibited by the
presence of glutamine. The fast action of glufosinate did not limit
its own translocation. Because glufosinate is highly water soluble,
it translocates mostly through the apoplast or the xylem system. Consequently,
old leaves tend to accumulate more herbicide than young meristematic
leaves.