Deep Evolutionary Comparison of Gene Expression Identifies Parallel Recruitment of Trans-Factors in Two Independent Origins of C4 Photosynthesis
As leaves of C. gynandra (A) and maize (B) mature, transcripts were classified into twenty-six behaviours, thirteen ascending (A&B) and thirteen descending. Statistically significant differences between neighbouring tissue types are delineated by red circles in ascending filters. The total number of genes within each behaviour is presented in parentheses and behaviours containing photosynthesis-related genes are annotated by red boxes around each plot (eg A3, A4 and A6). Genes of the core C4 cycle occupy six and five of the thirteen ascending filters in C. gynandra and maize respectively (transcripts in green). (C) Venn diagram representing transcription factors showing the same behaviours as C4-related genes in the maize and in C. gynandra leaf gradients. (D) Behaviour of homologous genes in C3 A. thaliana.