LIFE WITHOUT A HEART: PLANTS MEDIATE LONG-DISTANCE NUTRIENT TRANSPORT WITH AN OSMOTICALLY DRIVEN PRESSURE GRADIENT GENERATED BY A PROTON-SUCROSE SYMPORTER

Authors: BUSH, DANIEL; CHIOU, TIZYY-JEN - PLANT BIO UNIV ILL URBANA; CHEN, LISHAN - PLANT BIO UNIV ILL URBANA

Submitted to: Membrane Biophysics Advances in Coupled Membrane Transporters Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 10/17/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: A hallmark in the evolution of multicellular organisms was the appearance of organized tissue systems that specialize in distinct biological processes required for growth and replication. In the higher plant, for example, the leaf functions as the primary supplier of free energy and organic nutrients. The leaf is the so called "source" tissue because it contains the photosynthetic machinery which transforms light energy into useful biological energy and because much of that captured energy is exported from the leaf, in the form of sucrose and amino acids, to satisfy the biochemical needs of the heterotrophic cells. Likewise, the heterotrophic tissues specialize in other important processes, such as nutrient acquisition (roots) or reproduction (flowers, seed, fruit). The development of specialized tissue systems generated a need for long distance transport mechanisms which mediate organic nutrient flow between the various organs of the plant. This resource redistribution process is known as assimilate partitioning and it occurs within the plant's vascular system. Unlike the mechanical pumps of animals, plants utilize an osmotically-driven pressure gradient generated by a proton-sucrose symporter.