Sugar Uptake in Lily Pollen 12: A PROTON SYMPORT
AUTOR(ES)
Deshusses, Jacques
RESUMO
The data presented here are consistent with a proton-sugar co-transport in germinated pollen of Lilium longiflorum Thunb. Optimal uptake occurs at pH 5.0. A Km of 1.7 to 1.8 millimolar is obtained from the initial rate of pH change induced by sucrose uptake as well as from uptake of [U-14C]-sucrose. The energy of activation is - 11 kilocalories mole−1. The effect of several inhibitors and sugar competitors on [U-14C]sucrose and d-[U-14C] glucose uptake is given. The possibility of hydrolysis of sucrose prior to its transport into the pollen tube has been considered and reasons for choosing a sucrose-type uptake are presented. The possible in vivo significance of this co-transport process during pollen germination is discussed. Germinated pollen has features to recommend it as an experimental system of choice for studies of sugar uptake.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=425774Documentos Relacionados
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