Panel A shows radiolabeled sugar distribution throughout a poplar sapling. High sugar levels are red, and low levels are blue. Panel B shows greater sugar accumulation in the roots after the sapling's leaf is exposed to a hormone signaling attack.
Credit or Source: R. Ferrieri and M. Thorpe, Brookhaven National Laboratory
US DOE. May 2010. Biological Systems Science Division: A Division of the U.S. Department of Energy Office of Biological and Environmental Research, US Department of Energy Office of Science. (p. 3a) (website)