Mechanisms underlying the polyphyletic evolution of C4 photosynthesis Event

I will show that the C4 photosynthetic phenotype is accessible via multiple routes of phenotypic acquisition. However, despite this flexibility in the timing of trait acquisition, I will also present data consistent with the fact that independent lineages of C4 plant use homologous transcription factors to regulate C4 photosynthesis networks. I will go on to show that genes from C3 species contain cis-elements that are sufficient to generate the patterns of expression associated with C4 photosynthesis, and also that these cis-elements have repeatedly been used by independent lineages of C4 plant. Together these data argue for C4 evolution being facilitated by flexibility in the timing of trait acquisition, the presence of pre-existing mechanisms in C3 plants, but also that multiple independent lineages of C4 plant have used common paths of gene recruitment and regulation. These data will be discussed in the context of international efforts that aim to integrate C4 photosynthesis into C3 crops to increase their maximum yields.