Study Provides Insights on Maximizing Energy-Rich Lipid Content in Leaves

Plant hormones affect leaf senescence.

The Science

Energy-rich lipids—with two times more energy than carbohydrates or proteins—are life’s primary molecules for energy storage. Preventing the breakdown of lipids as leaves age during the process of senescence is estimated to increase the energy content of leaves by about 20%. Great Lakes Bioenergy Research Center researchers systematically studied the age-dependent changes in the fatty acids of Arabidopsis, Brachypodium distachyon (a model grass), and switchgrass leaves during natural plant senescence. Researchers found that surface lipids were more stable during senescence than membrane lipids, thus a potential strategy for increasing the energy content of biofuel crops might be to enhance surface lipid production.


During leaf senescence, macromolecule breakdown occurs and nutrients are translocated to support growth of new vegetative tissues, seeds, or other storage organs. In this study, researchers determined the fatty acid levels and profiles in Arabidopsis (Arabidopsis thaliana), Brachypodium  distachyon, and switchgrass (Panicum virgatum) leaves during natural senescence. In young leaves, fatty acids represent 4% to 5% of dry weight and approximately 10% of the chemical energy content of the leaf tissues. In all three species, fatty acid levels in leaves began to decline at the onset of leaf senescence and progressively decreased as senescence advanced, resulting in a greater than 80% decline in fatty acids on a dry weight basis.


Yang, Z., and J. B. Ohlrogge. 2009. “Turnover of Fatty Acids During Natural Senescence of Arabidopsis, Brachypodium, and Switchgrass and in Arabidopsis ?-Oxidation Mutants,” Plant Physiology 150, 1981–89. DOI:10.1104/pp.109.140491.