ARS | Publication request: TRIACYLGLYCEROL PHASE AND SEED STORAGE BEHAVIOR

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 30, 2006
Publication Date: July 20, 2006
Citation: Walters, C.T., Crane, J., Volk, G.M. 2006. Triacylglycerol phase and seed storage behavior. 17th International Symposium on Plant Lipids. July 16-21, 2006, East Lansing, Michigan. p. 67. Meeting Abstract.

Technical Abstract: Anecdotal stories have long suggested that oil-rich seeds store poorly; however, laboratory studies show that lipid content does not correlate with seed quality. Recently, we found that the tendency of triacylglycerols (TAG) to crystallize during storage of Cuphea seeds has a profound effect on seed survival. Seeds containing TAG with longer chain, saturated fatty acids are more susceptible to damage because crystallization occurs at relatively high temperatures. Imbibition of seeds with crystallized TAG leads to massive cellular disruption, possibly because the hydrophilic and hydrophobic interactions that stabilize oil bodies are altered by the phase change. TAG in planta crystallize slowly if the storage temperature is less than the crystallization temperature. The kinetics of TAG crystallization correspond to the rate of damage in stored Cuphea seeds. Moreover, a break in the effect of temperature on aging rate occurs near the TAG crystallization temperature. Collectively, these findings imply that greater saturation and longer fatty acid chains of TAG in seeds increases their susceptibility to deterioration during storage and imbibition. The implication is counter-intuitive because aging has traditionally been considered a result of peroxidative reactions, making seeds with polyunsaturated fatty acids most susceptible. Future studies of the interaction of TAG phase and seed quality will investigate the role of oil body architecture in TAG phase changes and the partitioning of free radicals and antioxidants in crystallized and fluid TAG.