Journal article

The sucrose transporter StSUT1 localizes to sieve elements in potato tuber phloem and influences tuber physiology and development

C Kuhn, MR Hajirezaei, AR Fernie, U Roessner-Tunali, T Czechowski, B Hirner, WB Frommer

PLANT PHYSIOLOGY | OXFORD UNIV PRESS INC | Published : 2003

Abstract

The sucrose (Suc) H(+)-cotransporter StSUT1 from potato (Solanum tuberosum), which is essential for long-distance transport of Suc and assumed to play a role in phloem loading in mature leaves, was found to be expressed in sink tubers. To answer the question of whether SUT1 serves a function in phloem unloading in tubers, the promoter was fused to gusA and expression was analyzed in transgenic potato. SUT1 expression was unexpectedly detected not in tuber parenchyma but in the phloem of sink tubers. Immunolocalization demonstrated that StSUT1 protein was present only in sieve elements of sink tubers, cells normally involved in export of Suc from the phloem to supply developing tubers, raisin..

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University of Melbourne Researchers