Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
Trends Plant Sci. 2012 Apr;17(4):213-20. doi: 10.1016/j.tplants.2012.01.008. Epub 2012 Feb 9.
The C₄ pathway is found in 62 lineages of land plants. We assess evidence for parallel versus convergent evolution of C₄ photosynthesis from three approaches: (i) studies of specific genes and cis-elements controlling their expression; (ii) phylogenetic analyses of mRNAs and inferred amino acid sequences; and (iii) analysis of C₃ and C₄ genomes and transcriptomes. Evidence suggests that although convergent evolution is common, parallel evolution can underlie both changes to gene expression and amino acid sequence. cis-elements that direct cell specificity in C₄ leaves are present in C₃ orthologues of genes recruited into C₄, probably facilitating this parallel evolution. From this, and genomic data, we propose that gene duplication followed by neofunctionalisation is not necessarily important in the evolution of C₄ biochemistry.
C₄ 途径存在于 62 个陆地植物谱系中。我们从三个方面评估 C₄ 光合作用的平行进化和趋同进化的证据：（i）研究控制其表达的特定基因和顺式元件；（ii）对 mRNA 和推断的氨基酸序列进行系统发育分析；以及（iii）对 C₃ 和 C₄ 基因组和转录组的分析。有证据表明，尽管趋同进化很常见，但平行进化可以为基因表达和氨基酸序列的变化提供基础。在被招募到 C₄ 中的基因的 C₃ 同源物中存在指导 C₄ 叶片细胞特异性的顺式元件，这可能有助于这种平行进化。由此以及基因组数据，我们提出，基因复制后功能化不一定是 C₄ 生物化学进化的重要因素。
