2025/10/21 by Hao Xu, Chao Shen, Wen‐Zhuan Huang +13 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Chromosomal and Genetic Variations #Genomics and Phylogenetic Studies #Photosynthetic Processes and Mechanisms
paper · doi:10.1111/nph.70672
openalex created_date 2025/10/21 · openalex publication_date 2025/10/21 · openalex updated_date 2026/07/28
Hornworts (Anthocerotophyta) represent a key lineage for understanding fundamental questions in land plant evolution, but their phylogeny and evolutionary history are still not well understood, primarily due to limited genomic resources and insufficient taxon sampling. We conducted comparative genomic analyses of 106 hornwort plastid genomes, including 91 newly generated ones. RNA editing sites were identified by integrating transcriptome data and in silico predictions. Additionally, a new method inspired by marker-capture strategies was proposed to estimate the total number of U-to-C editing sites. Hornwort plastomes are larger than those of liverworts and mosses, with rare gene loss or pseudogenization. Both C-to-U and U-to-C RNA editing occur across all lineages except Leiosporoceros. Diversification rate analyses indicate a major shift between c. 100 and 50 million years ago, possibly linked to the Cretaceous-Paleogene extinction event. Both morphological and molecular evidence support the merging of Folioceros into Anthoceros, and the recognition of two new species in the small genera Paraphymatoceros and Phymatoceros, respectively. This study presents the first large-scale plastome phylogeny of hornworts, introduces a DNA-only method for estimating the number of U-to-C RNA editing sites, and updates the classification. These results contribute broadly to our understanding of early land plant evolution.