Genome-Wide Analysis of Somatic Embryogenesis-Related Transcription Factors in Cultivated Strawberry (Fragaria × ananassa) and Evolutionary Relationships among Rosaceae Species

Abstract

Somatic embryogenesis is a plant regeneration method commonly used in tissue culture. Its molecular mechanisms are well-known in model plants such as Arabidopsis thaliana L. LEAFY COTYLEDON1 (LEC1), LEAFY COTYLEDON2 (LEC2), FUSCA3 (FUS3), ABSCISIC ACID INSENSITIVE3 (ABI3), and BABYBOOM (BBM) genes are considered master regulators in the induction, growth, and maturation of somatic embryos. However, the study of these transcription factors in fruit crops with high agronomic and economic value such as cultivated strawberry (Fragaria × ananassa Duch.) and other Rosaceae species is scarce. The purpose of this study was the in silico characterization of LEC1, ABI3, FUS3, LEC2, and BBM(LAFL-B) genes from F. × ananassa genome and the study of the evolutionary relationships within the Rosaceae family. Synteny analyses and molecular evolutionary rates were performed to analyze the evolution of each transcription factor within the Rosaceae family. Synteny was conserved between F. × ananassa and other Rosaceae genomes, and paralogous genes were selected through negative selection. Additionally, the exon–intron organization and multiple alignments showed that gene structure and DNA-binding domains were conserved in F. × ananassa transcription factors. Finally, phylogenetic trees showed close evolutionary relationships between F. × ananassa and its orthologous proteins in the Rosoideae subfamily. Overall, this research revealed novel insights in the LAFL-B network in F. × ananassa and other species of the Rosaceae family. These results provide useful in silico information and new resources for the establishment of more efficient propagation systems or the study of ploidy effects on somatic embryogenesis.