Sugar Pump in Plants Identified

Scientists at the Max Planck Institute of Molecular Plant Physiology led by Alisdair Fernie discovered a protein that transports sucrose to the plant's vascular pathways.

Carbon is transported in plants in the form of sucrose, which is produced in mesophyll cells and imported into the phloem for distribution in different cells of the plant. However, how sucrose migrates from mesophyll to the phloem was not yet known. Thus, Fernie and colleagues used optical sucrose sensors and identifies a subfamily of SWEET sucrose efflux transpoters. AtSWEET11 and 12 were found in the plasma membrane of the phloem. Mutant Arabidopsis and rice plants with switched off AtSWEET11 and 12 exhibited defective phloem loading and accumulation of sucrose in the leaves. This build up indicates failure in transport of sucrose, and thus the other parts of the plant are lacking sucrose supply. Results of this study can be used to increase the sucrose content of plant seeds leading to higher harvest yield.

For more information, read the articles at http://www.mpg.de/4693267/sugar_pump_plants and http://www.sciencemag.org/content/early/2011/12/07/science.1213351