Open AccessPositive selection drives adaptive diversification of the 4‐coumarate: CoA ligase ( 4 CL ) gene in angiosperms
Author(s) -
Sun Haiyan,
Guo Kai,
Feng Shengqiu,
Zou Weihua,
Li Ying,
Fan Chunfen,
Peng Liangcai
Publication year - 2015
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.1613
Subject(s) - nonsynonymous substitution , biology , negative selection , phylogenetic tree , abiotic component , functional divergence , biochemistry , gene , phylogenetics , biosynthesis , dna ligase , genetics , computational biology , ecology , gene family , genome
Lignin and flavonoids play a vital role in the adaption of plants to a terrestrial environment. 4‐Coumarate: coenzyme A ligase (4 CL ) is a key enzyme of general phenylpropanoid metabolism which provides the precursors for both lignin and flavonoids biosynthesis. However, very little is known about how such essential enzymatic functions evolve and diversify. Here, we analyze 4 CL sequence variation patterns in a phylogenetic framework to further identify the evolutionary forces that lead to functional divergence. The results reveal that lignin‐biosynthetic 4 CL s are under positive selection. The majority of the positively selected sites are located in the substrate‐binding pocket and the catalytic center, indicating that nonsynonymous substitutions might contribute to the functional evolution of 4 CL s for lignin biosynthesis. The evolution of 4 CL s involved in flavonoid biosynthesis is constrained by purifying selection and maintains the ancestral role of the protein in response to biotic and abiotic factors. Overall, our results demonstrate that protein sequence evolution via positive selection is an important evolutionary force driving adaptive diversification in 4 CL proteins in angiosperms. This diversification is associated with adaption to a terrestrial environment.