Relationships between chemical structure and phloem mobility in Ricinus communis var. Gibsonii with reference to a series of ω‐(1‐naphthoxy)alkanoic acids

Abstract

AbstractThe phloem translocation of an homologous series of ω‐(1‐[1‐4C]naphthoxy)alkanoic acids relative to that of applied [6,6′‐3H] sucrose was measured in Ricinus communis var. Gibsonii. Relative phloem mobility decreased with increase in octan‐l‐ol/water partition coefficients. However, non‐ionisable compounds with partition coefficients similar to the readily translocated acids were not phloem mobile. These results are explained in terms of an ion‐trap mechanism subject to limitations on the partition coefficients of the acids and possibly their anions.