Journal article
SUT2, a Putative Sucrose Sensor in Sieve Elements
The Plant cell, Vol.12(7), pp.1153-1164
07/2000
Handle:
https://hdl.handle.net/2376/113308
PMCID: PMC149056
PMID: 10899981
Abstract
In leaves, sucrose uptake kinetics involve high- and low-affinity components. A family of low- and high-affinity sucrose transporters (SUT) was identified. SUT1 serves as a high-affinity transporter essential for phloem loading and long-distance transport in solanaceous species. SUT4 is a low-affinity transporter with an expression pattern overlapping that of SUT1. Both SUT1 and SUT4 localize to enucleate sieve elements of tomato. New sucrose transporter–like proteins, named SUT2, from tomato and Arabidopsis contain extended cytoplasmic domains, thus structurally resembling the yeast sugar sensors SNF3 and RGT2. Features common to these sensors are low codon bias, environment of the start codon, low expression, and lack of detectable transport activity. In contrast to
LeSUT1
, which is induced during the sink-to-source transition of leaves,
SUT2
is more highly expressed in sink than in source leaves and is inducible by sucrose. LeSUT2 protein colocalizes with the low- and high-affinity sucrose transporters in sieve elements of tomato petioles, indicating that multiple SUT mRNAs or proteins travel from companion cells to enucleate sieve elements. The
SUT2
gene maps on chromosome V of potato and is linked to a major quantitative trait locus for tuber starch content and yield. Thus, the putative sugar sensor identified colocalizes with two other sucrose transporters, differs from them in kinetic properties, and potentially regulates the relative activity of low- and high-affinity sucrose transport into sieve elements.
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Details
- Title
- SUT2, a Putative Sucrose Sensor in Sieve Elements
- Creators
- Laurence Barker - Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, GermanyChristina Kühn - Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, GermanyAndreas Weise - Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, GermanyAlexander Schulz - Department of Plant Biology, Royal Veterinary and Agricultural University, KVL, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen, DenmarkChristiane Gebhardt - Max Planck Institut für Züchtungsforschung, Carl von Linné Weg 10, 50829 Cologne, GermanyBrigitte Hirner - Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, GermanyHanjo Hellmann - Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, GermanyWaltraud Schulze - Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, GermanyJohn M Ward - Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, GermanyWolf B Frommer - Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP), Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, Germany
- Publication Details
- The Plant cell, Vol.12(7), pp.1153-1164
- Academic Unit
- Biological Sciences, School of
- Publisher
- American Society of Plant Physiologists
- Identifiers
- 99900547847801842
- Language
- English
- Resource Type
- Journal article