Determination of 3-Hydroxy-3-methylglutaryl CoA Reductase Activity in Plants

The enzyme 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase catalyzes the NADPH-mediated reductive deacylation of HMG-CoA to mevalonic acid, which is the first committed step of the mevalonate pathway for isoprenoid biosynthesis. In agreement with its key regulatory role in the pathway, plant HMG-CoA reductase is modulated by many diverse external stimuli and endogenous factors and can be detected to variable levels in every plant tissue. A fine determination of HMG-CoA reductase activity levels is required to understand its contribution to plant development and adaptation to changing environmental conditions. Here, we report a procedure to reliably determine HMG-CoA reductase activity in plants. The method includes the sample collection and homogenization strategies as well as the specific activity determination based on a classical radiochemical assay.This work was supported by grants of the Spanish Ministerio de Economía y Competitividad and the Spanish Ministerio de Ciencia e Innovación (BFU2011-24208 to N.C., BIO2009-06984 to A.F. and M.A., and BIO2009-09523 to A.B., including FEDER funds), the Spanish Consolider-Ingenio Program (CSD2007-00036 Centre for Research in Agrigenomics), and the Generalitat de Catalunya (2009SGR0026).Peer reviewe