Written by: Lauren Perkins September 29, 2022 Dr. Paul Wolf, Chair of the Department of Biological Sciences, professor, and plant geneticist, and graduate student Rijan Dhakal, among several other researchers, recently had their research published in Nature Plants on "dynamic genome evolution in a model fern." A fern is a vascular plant that does not have flowers nor seeds. Ferns reproduce by releasing spores onto fertile ground. Ferns are a very ancient family of plants. They predate the beginning of the Mesozoic era. For perspective, ferns were around when the dinosaurs roamed the Earth. Ferns have shaped life on Earth since divergence from their common ancestor with seed plants over 360 million years ago. Ferns can be found across diverse ecosystems as colonizers, keystone species, invasives and agricultural supplements. "Over 100 plant genomes have been published and most are from economically important crop species such as rice, wheat, and corn," Dr. Wolf says. Previously hindered by their notoriously large genomes and number chromosomes, scientists and researchers are finally delving into seed plant genomes: mosses, ferns, club mosses; over 20 years since the first plant genome was sequenced. Analysis by this team of researchers of the Ceratopteris richardii or C-fern genome provides hints for solving the long-standing mystery of why ferns, on average, retain more DNA than other plants. This is one of the largest haploid genomes with a chromosomal assembly to date, surpassed only by the assembly of the giant sequoia (Sequoiadendron giganteum) genome. Wolf and Dhakal "are exploring patterns of gene distribution to see if we can find clues to what factors control chromosome numbers in plants." Accompanying enormous morphological and ecological diversity, ferns have evolved numerous adaptations for protection from environmental stresses. Ferns and their associated genes provide valuable resources for bioremediation, agricultural applications and lifesaving drugs: The identification of genes contributing to reproduction in homosporous ferns and their expression patterns can elucidate the evolution and potential origin of genes driving shifts in the reproductive biology of heterosporous ferns and seed plants. Novel biopesticides have been discovered in a number of fern species and have benefited sustainable agriculture and food security. Ferns have long been used in traditional medicine worldwide and more recently have been a source for bioprospecting medicinal compounds to treat cancer, diabetes and osteoarthritis. However, the lack of a high-quality reference genome of a homosporous fern species has hindered the research and development of novel fern compounds for medicinal application. Their research was also highlighted in Science Magazine and the Florida Museum of Natural History.
