Please use this identifier to cite or link to this item:
|Scopus||Web of Science®||Altmetric|
|Title:||Role of membrane transport in phloem translocation of assimilates and water|
|Citation:||Functional Plant Biology, 2001; 28(7):695-707|
|Publisher:||C S I R O Publishing|
|John W. Patrick, Wenhao Zhang, Stephen D. Tyerman, Christina E. Offler and N. Alan Walker|
|Abstract:||Most growth and storage organs (sinks) of higher plants import assimilates in solution by bulk flow through the phloem, driven by differences in hydrostatic pressure. These differences in pressure, located between the ends of the interconnecting phloem path, are generated by osmotic water movement, driven in turn by membrane transport of solutes. Sucrose, amino-nitrogen compounds and potassium represent the osmotically important solutes found in phloem contents of most species. Phloem loading and unloading events of these assimilate species play central roles in determining phloem translocation rates and partitioning of assimilates and water. Depending on plant species, leaf vein order and sink type, phloem loading and unloading may follow apoplasmic or symplasmic routes. Irrespective of the cellular pathway followed, assimilates are transported across plasma and organellar membranes. Aquaporins, amino-nitrogen transporters, sucrose transporters and potassium channels have been detected in key sites along the source–phloem–sink transport pathway. Reverse genetics has demonstrated that sucrose/proton symporters are important in transport events necessary for phloem loading in Solanaceousplant species. Drawing on circumstantial evidence, we review possible functions the remaining membrane transporters and channels may serve in driving phloem translocation of assimilates and water from source to sink.|
|Rights:||© CSIRO 2001|
|Appears in Collections:||Agriculture, Food and Wine publications|
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.