title: Revisiting the phosphatidylethanolamine-binding protein (PEBP) gene family reveals cryptic FLOWERING LOCUS T gene homologs in gymnosperms and sheds new light on functional evolution.
abstract: Angiosperms and gymnosperms are two major groups of extant seed plants. It has been suggested that gymnosperms lack FLOWERING LOCUS T (FT), a key integrator at the core of flowering pathways in angiosperms. Taking advantage of newly released gymnosperm genomes, we revisited the evolutionary history of the plant phosphatidylethanolamine-binding protein (PEBP) gene family through phylogenetic reconstruction. Expression patterns in three gymnosperm taxa and heterologous expression in Arabidopsis were studied to investigate the functions of gymnosperm FT-like and TERMINAL FLOWER 1 (TFL1)-like genes. Phylogenetic reconstruction suggests that an ancient gene duplication predating the divergence of seed plants gave rise to the FT and TFL1 genes. Expression patterns indicate that gymnosperm TFL1-like genes play a role in the reproductive development process, while GymFT1 and GymFT2, the FT-like genes resulting from a duplication event in the common ancestor of gymnosperms, function in both growth rhythm and sexual development pathways. When expressed in Arabidopsis, both spruce FT-like and TFL1-like genes repressed flowering. Our study demonstrates that gymnosperms do have FT-like and TFL1-like genes. Frequent gene and genome duplications contributed significantly to the expansion of the plant PEBP gene family. The expression patterns of gymnosperm PEBP genes provide novel insight into the functional evolution of this gene family.
authors.affiliation: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|University of the Chinese Academy of Sciences, Beijing, 100039, China.
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Liu
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Ke-Zhen
authors.initials: KZ
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China. weixx@ibcas.ac.cn.
authors.forename: Xiao-Xin
authors.initials: XX
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Xiao-Quan
authors.initials: XQ
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D032462:Cycadopsida / Q000235:genetics*; D019143:Evolution, Molecular; D035264:Flowers / Q000235:genetics*; D018628:Gene Dosage; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D016013:Likelihood Functions; D005810:Multigene Family; D010641:Phenotype; D049488:Phosphatidylethanolamine Binding Protein / Q000737:chemistry / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified
chemical_list: D049488:Phosphatidylethanolamine Binding Protein; D010940:Plant Proteins
keywords: FLOWERING LOCUS T (FT); functional evolution; gene and genome duplication; gymnosperms; molecular phylogeny; phosphatidylethanolamine-binding protein (PEBP) gene family; seed plants