Abstract Detail

Pteridology

Hernandez-Hernandez, Brenda [1], Tapia-Lopez, Rosalinda [2], Ambrose, Barbara [3], Vasco, Alejandra [4].

R2R3-MYB gene evolution in plants, incorporating ferns into the story.

Premise of the Research. MYB transcription factors comprise a large family in flowering plants and are involved in many regulatory processes such as primary and secondary metabolism, cell fate and identity, developmental processes, and responses to biotic and abiotic stresses. Phylogenetic studies have focused on R2R3-MYB evolution mainly in seed plants; however, a comprehensive sampling across land plants is lacking as none have included ferns. Methods. To better understand the evolution of R2R3-MYB genes in land plants, we surveyed the R2R3-MYB gene sequences from six genomes belonging to the main lineages of land plants (bryophytes, lycophytes, ferns, angiosperms, and gymnosperms). In addition, we searched transcriptome sequences of selected lycophyte transcriptomes. We assembled a nucleotide matrix of the MYB domain and conducted phylogenetic analyses to infer evolutionary relationships. We labelled the main clades with the known MYB functions onto the resulting tree. To detect reported as well as new conserved motifs, we ran protein motif analyses through MEME. Results. Our phylogeny recovered 21 main clades of which 14 include fern sequences. Most of the R2R3-MYB clades containing fern sequences were already present in the ancestor of land plants. Many of the R2R3-MYB copies found in ferns are the result of fern-specific duplications. Protein motif analyses revealed R2R3-MYB motifs are highly conserved across land plants, suggesting that R2R3-MYB fern orthologs might have DNA binding capabilities and could be involved in similar regulatory processes as their angiosperm homologs. Our analyses showed there are no fern orthologs of the angiosperm MYB leaf developmental genes ARP, raising interesting questions about the evolution and origin of leaves in ferns and seed plants. Conclusions. Our results provide the phylogenetic context for research in the genetic and functional evolution of an important gene family of developmental and metabolic regulators across the plant tree of life.

1 - Institute of Biology, Botany, UNAM, Mexico City, 04510
2 - Universidad Nacional Autónoma de México (UNAM), Department of Evolutionary Ecology, Instituto de Ecología, Mexico City, Mexico
3 - The New York Botanical Garden, 2900 Southern Blvd., Bronx, NY, 10458, United States
4 - Botanical Research Institute Of Texas, 1700 University Drive, Fort Worth, TX, 76107, United States

Keywords:
Asymmetric leaves 1
leaf development
Myb genes
transcription factors.

Presentation Type: Poster
Session: P, Pteridology Posters
Location: Virtual/Virtual
Date: Monday, July 27th, 2020
Time: 5:00 PM Time and date to be determined
Number: PPT002
Abstract ID:748
Candidate for Awards:None