caa a22 4500 477101771 CHVBK 20180405111544.0 cr unu---uuuuu 170330e19960801xx s 000 0 eng 10.1007/BF00195190 doi (NATIONALLICENCE)springer-10.1007/BF00195190 Transfer of exogenous auxin from the phloem to the polar auxin transport pathway in pea ( Pisum sativum L.) [Elektronische Daten] [Amanda Cambridge, David Morris] When [1-14C]indol-3yl-acetic acid ([1-14C]IAA) was applied to the upper surface of a mature foliage leaf of garden pea (Pisum sativum L. cv. Alderman), 14C effluxed basipetally but not acropetally from 30-mm-long internode segments excised 4 h after the application of [1-14C]IAA. This basipetal efflux was strongly inhibited by the inclusion of 3.10−6 mol· dm3 N-1-naphthylphthalamic acid (NPA) in the efflux buffer. In contrast, when [14C] sucrose was applied to the leaf, the efflux of label from stem segments excised subsequently was neither polar nor sensitive to NPA. The [1-14C]IAA was initially exported from mature leaves in the phloem — transport was rapid and apolar; label was recovered from aphids feeding on the stem; and label was recovered in exudates collected from severed petioles in 20 mM ethylenediaminetetraacetic acid. No 14C was detected in aphids feeding on the stems of plants to which [1-14C]IAA had been applied apically, even though the internode on which they were feeding transported considerable quantities of label. Localised applications of NPA to the stem strongly inhibited the basipetal transport of apically applied [1-14C]IAA, but did not affect transport of [1-14C]IAA in the phloem. These results demonstrate for the first time that IAA exported from leaves in the phloem can be transferred into the extravascular polar auxin transport pathway but that reciprocal transfer probably does not occur. In intact plants, transfer of foliar-applied [1-14C]IAA from the phloem to the polar auxin transport pathway was confined to immature tissues at the shoot apex. In plants in which all tissues above the fed leaf were removed before labelling, a limited transfer of IAA occurred in more mature regions of the stem. Springer-Verlag, 1996 Auxins (transport) nationallicence Phloem exudate nationallicence Phloem transport (auxins) nationallicence Pisum nationallicence Polar transport (auxins) nationallicence IAA : indol-3yl-acetic acid nationallicence EDTA : ethylenediaminetetraacetic acid nationallicence NPA : N-1-naphthylphthalamic acid nationallicence Cambridge Amanda Department of Biology, School of Biological Sciences, University of Southampton, Biomedical Sciences Building, Bassett Crescent East, SO16 7PX, Southampton, UK aut Morris David Department of Biology, School of Biological Sciences, University of Southampton, Biomedical Sciences Building, Bassett Crescent East, SO16 7PX, Southampton, UK aut Planta Springer-Verlag 199/4(1996-08-01), 583-588 0032-0935 199:4<583 1996 199 425 https://doi.org/10.1007/BF00195190 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00195190 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cambridge Amanda Department of Biology, School of Biological Sciences, University of Southampton, Biomedical Sciences Building, Bassett Crescent East, SO16 7PX, Southampton, UK aut NATIONALLICENCE 700 1- Morris David Department of Biology, School of Biological Sciences, University of Southampton, Biomedical Sciences Building, Bassett Crescent East, SO16 7PX, Southampton, UK aut NATIONALLICENCE 773 0- Planta Springer-Verlag 199/4(1996-08-01), 583-588 0032-0935 199:4<583 1996 199 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer