C4 and CAM: from molecular diversity to ecological convergence

DRINCOVICH, M.F.; ALVAREZ, C.E.; DETARSIO, E.; ANDREO, C.S.

Cambridge

Congreso; Department of Plant Sciences, University of Cambridge, UK. Julio 17 -20, 2007; 2007

Department of Plant Sciences, University of Cambridge

C4 photosynthetic NADP-malic enzyme has evolved from non-C4 isoforms during evolution. In maize, the plastidic non-photosynthetic NADP-ME represents the more recent and direct ancestor of the C4–isoform. Although the high sequence similarity (85%) between these two NADP-MEs, they display well distinct kinetic and structural properties. In order to identify possible differences in response to -SH oxidation, recombinant C4- and non-C4 NADP-ME were subjected to oxidation and further reduction. Incubation of maize C4 NADP-ME with the oxidant o-iodosobenzoate (IBZ) leads to the complete inactivation of the enzyme.