1. Introduction
Over sixty lineages of both monocot and eudicot angiosperms
have evolved a remarkable solution to maximize photosynthesis
efficiency under low CO2 levels, high temperatures and/or drought:
C4 photosynthesis [1]. The evolution of this modified photosynthetic
pathway represents a wonderful example of convergent
evolution. While the changes necessary for the transition from C3
to C4 photosynthesis are numerous, the trait has a wide phylogenetic
distribution across angiosperms, with 19 different plant
was used. Gene and genome duplications and the origin of C4 photosynthesis: Birth of a trait in the Cleomaceae