Convergent molecular evolution of phosphoenolpyruvate carboxylase gene family in C 4 and crassulacean acid metabolism plants

PeerJ

article

Jiang-Ping Shu¹  Yue-Hong Yan²  Rui-Jiang Wang¹ 

[1] Key laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences;Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization, The National Orchid Conservation Centre of China and The Orchid Conservation and Research Centre of Shenzhen;Shenzhen Key Laboratory for Orchid Conservation and Utilization, The National Orchid Conservation Centre of China and The Orchid Conservation and Research Centre of Shenzhen;University of Chinese Academy of Sciences

关键词: PEPC;    Convergent evolution;    Carbon-concentrating mechanisms;    Photosynthetic convergence;    Phylogeny;   

DOI  :  10.7717/peerj.12828

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Phosphoenolpyruvate carboxylase (PEPC), as the key enzyme in initial carbon fixation of C4and crassulacean acid mechanism (CAM) pathways, was thought to undergo convergent adaptive changes resulting in the convergent evolution of C4 and CAM photosynthesis in vascular plants. However, the integral evolutionary history and convergence of PEPC in plants remain poorly understood. In the present study, we identified the members of PEPC gene family across green plants with seventeen genomic datasets, found ten conserved motifs and modeled three-dimensional protein structures of 90 plant-type PEPC genes. After reconstructing PEPC gene family tree and reconciled with species tree, we found PEPC genes underwent 71 gene duplication events and 16 gene loss events, which might result from whole-genome duplication events in plants. Based on the phylogenetic tree of the PEPC gene family, we detected four convergent evolution sites of PEPC in C4 species but none in CAM species. The PEPC gene family was ubiquitous and highly conservative in green plants. After originating from gene duplication of ancestral C3-PEPC, C4-PEPC isoforms underwent convergent molecular substitution that might facilitate the convergent evolution of C4 photosynthesis in Angiosperms. However, there was no evidence for convergent molecular evolution of PEPC genes between CAM plants. Our findings help to understand the origin and convergent evolution of C4 and CAM plants and shed light on the adaptation of plants in dry, hot environments.

【 授权许可】

CC BY