Project description:Background The Lycophyta species are the extant taxa most similar to early vascular plants that were once abundant on Earth. However, their distribution has greatly diminished. So far, the absence of chromosome level assembled lycophyte genomes, has hindered our understanding of evolution and environmental adaption of lycophytes. Findings We present the reference genome of the tetraploid aquatic quillwort, Isoetes sinensis, a lycophyte. This genome represents the first chromosome-level assembled genome of a tetraploid seed-free plant. Comparison of genomes between I. sinensis and the diploid I. taiwanensis revealed of genomic features and polyploid of lycophytes. Comparison of the I. sinensis genome with those of other species representing the evolutionary lineages of green plants revealed the inherited genetic tools for transcriptional regulation and most phytohormones in I. sinensis. The presence and absence of key genes related to development and stress responses provides insights into environmental adaption of lycophytes. Conclusions The high-quality reference genome and genomic analysis presented in this study are crucial for future genetic research and the conservation of not only I. sinensis but also other lycophytes.
