caa a22 4500 477101046 CHVBK 20180405111541.0 cr unu---uuuuu 170330e19960401xx s 000 0 eng 10.1007/BF00262635 doi (NATIONALLICENCE)springer-10.1007/BF00262635 Sugar uptake by the dermal transfer cells of developing cotyledons of Vicia faba L [Elektronische Daten] Mechanism of energy coupling [R. McDonald, S. Fieuw, J. Patrick] The mechanism of carrier-mediated sucrose uptake by the dermal transfer cells of developing Vicia faba L. cotyledons was studied using excised cotyledons and isolated transfer cell protoplasts. Addition of sucrose resulted in a transitory alkalinization of the bathing solution whereas additions of glucose, fructose or raffinose had no effect. Dissipating the proton motive force by exposing cotyledons and isolated transfer cell protoplasts to an alkaline pH, carbonylcyanide m-chlorophenylhydrazone, weak acids (propionic acid and 5,5′-dimethyl-oxazolidine-2,4-dione) or tetraphenylphos-phonium ion resulted in a significant reduction of sucrose uptake. The ATPase inhibitors, erythrosin B (EB), diethylstilbestrol (DES) and N,N′-dicyclohexylcarbodiimide (DCCD) were found to abolish the sucrose-induced medium alkanization as well as reduce sucrose uptake. Cytochemical localization of the ATPase, based on lead precipitation, demonstrated that the highest activity was present in the plasma membranes located in wall ingrowth regions of the dermal transfer cells. The presence of a transplasma-membrane redox system was detected by the extracellular reduction of the electron acceptor, hexacyanoferrate III. The reduction of the ferric ion was coupled to a release of protons. The redox-induced proton extrusion was abolished by the ATPase inhibitors EB, DES and DCCD suggesting that proton extrusion was solely through the H+-ATPase. Based on these findings, it is postulated that cotyledonary dermal transfer cells take up sucrose by a proton symport mechanism with the proton motive force being generated by a H + -ATPase. Sucrose uptake by the storage parenchyma and inner epidermal cells of the cotyledons did not exhibit characteristics consistent with sucrose-proton symport. Springer-Verlag, 1996 Cotyledon (developing Vicia ) nationallicence Dermal transfer cells nationallicence Plasma membrane ATPase nationallicence Proton motive force nationallicence Proton sucrose symport nationallicence Vicia (sugar uptake) nationallicence CCCP : carbonylcyanide m-chlorophenylhydrazone nationallicence DCCD : N,N′-dicyclohexylcarbodiimide nationallicence DES : diethylstilbestrol nationallicence EB : erythrosin B nationallicence Em : membrane potential nationallicence FC : fusicoccin nationallicence HCF II : hexacyanoferrate II nationallicence HCF III : hexacyanoferrate III nationallicence Mes : 2-(N-morpholino)ethanesulfonic acid nationallicence pmf : proton motive force nationallicence TPP+ : tetraphenylphosphonium ion nationallicence McDonald R. Department of Biological Sciences, The University of Newcastle, 2308, NSW, Australia aut Fieuw S. Department of Biological Sciences, The University of Newcastle, 2308, NSW, Australia aut Patrick J. Department of Biological Sciences, The University of Newcastle, 2308, NSW, Australia aut Planta Springer-Verlag 198/4(1996-04-01), 502-509 0032-0935 198:4<502 1996 198 425 https://doi.org/10.1007/BF00262635 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00262635 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- McDonald R. Department of Biological Sciences, The University of Newcastle, 2308, NSW, Australia aut NATIONALLICENCE 700 1- Fieuw S. Department of Biological Sciences, The University of Newcastle, 2308, NSW, Australia aut NATIONALLICENCE 700 1- Patrick J. Department of Biological Sciences, The University of Newcastle, 2308, NSW, Australia aut NATIONALLICENCE 773 0- Planta Springer-Verlag 198/4(1996-04-01), 502-509 0032-0935 198:4<502 1996 198 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 477100554 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer