Highly expressed genes are preferentially co-opted for C4 photosynthesis
One of the great questions of biology is how and why C4 photosynthesis pathway evolved independently more than 60 times. The advantages are obvious (increased productivity), but the underlying molecular predisposition to this transition remains poorly defined. Using a comparative transcriptomics approach involving the non-C4 relatives of C4 plants, Moreno-Villena et al. found that the members of gene families that were co-opted for C4 photosynthesis were those that were more highly expressed in the non-C4 ancestors. “The co-option, likely dictated by the mere presence of each protein in leaves, was followed by massive upregulation and widespread adaptation of coding sequences.” Mol. Biol. Evol. 10.1093/molbev/msx269