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. 1979 Apr;63(4):744–748. doi: 10.1104/pp.63.4.744

Phloem Loading of Sucrose

Involvement of Membrane ATPase and Proton Transport 1

Robert T Giaquinta a
PMCID: PMC542909  PMID: 16660804

Abstract

p-Chloromercuribenzenesulfonic acid markedly inhibited sucrose accumulation into sugar beet source leaves without inhibiting hexose accumulation. The site of inhibition is proposed to be the plasmalemma ATPase, since the ATPase-mediated H+ efflux was completely inhibited by p-chloromercuribenzenesulfonic acid under conditions where intracellular metabolism, as measured by photosynthesis and hexose accumulation, was unaffected. Fusicoccin, a potent activator of active H+/K+ exchange, stimulated both active sucrose accumulation and proton efflux in the sugar beet leaf tissue. These data provide strong evidence for the phloem loading of sucrose being coupled to a proton transport mechanism driven by a vectorial plasmalemma ATPase.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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