Different contribution of mitochondrial metabolism to synthesis of lipid in soybean and castor seeds

GERRARD WHEELER, M. C.; RIGHINI ARAMBURU, S.; ARIAS, C. L.; DRINCOVICH, M. F.; ANDREO, C. S.; SAIGO, M.

Rosario

Congreso; L Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología MolecularFisiología Vegetal; 2014

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Soybean and castor bean seeds have important roles providing feedstocks for human and animal diet and industrial processing. In these oilseeds the synthesis de novo of the fatty acids occurs in the plastids and requires precursors generated in the cytosol mainly by glycolisis. Malate is a carbon transporter molecule abundant in plant tissues that supplies carbon skeletons and reductive power for fatty acids synthesis through the action of a plastidic malic enzyme (ME). In this work we studied the ME families of soybean and castor bean. The comparison of the family members, expression patterns, enzymatic activities and organic acids contents reveal differences in the roles of the MEs in these oilseeds. Most significantly, mitochondrial NAD-ME has shown an important role in the maturation of soybean seeds driving the relocation of carbon skeletons from mitochondria to plastids to support the fatty acids synthesis in the last stages of seed filling.