Biochemical approaches to C4 photosynthesis evolution studies: the case of malic enzymes decarboxylases

MARIANA SAIGO; MARCOS A TRONCONI; MARIEL GERRARD WHEELER; CLARISA E. ALVAREZ; MARIA FABIANA DRINCOVICH; CARLOS SANTIAGO ANDREO

PHOTOSYNTHESIS RESEARCH

SPRINGER

Lugar: Berlin; Año: 2013 vol. 117 p. 177 - 187

0166-8595

C4 photosynthesis enables the capture ofatmospheric CO2 and its concentration at the site ofRuBisCO, thus counteracting the negative effects of lowatmospheric levels of CO2 and high atmospheric levels ofO2 (21 %) on photosynthesis. The evolution of this complexsyndrome was a multistep process. It did not occur bysimply recruiting pre-exiting components of the pathwayfrom C3 ancestors which were already optimized for C4function. Rather it involved modifications in the kineticsand regulatory properties of pre-existing isoforms of nonphotosyntheticenzymes in C3 plants. Thus, biochemicalstudies aimed at elucidating the functional adaptations ofthese enzymes are central to the development of an integrativeview of the C4 mechanism. In the present review, themost important biochemical approaches that we currentlyuse to understand the evolution of the C4 isoforms of malicenzyme are summarized. It is expected that this informationwill help in the rational design of the best decarboxylationprocesses to provide CO2 for RuBisCO in engineering C3species to perform C4 photosynthesis.