Format: ORAL

Li-Yaung Kuo1, Huei-Jiun Su2, Yu-Hsin Tseng3, Blake D. Fauskee4, Pei-Jun Xie1, Atsushi Ebihara5, Yi-Han Chang6

1 Institute of Molecular & Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan 2 Department of Earth and Life Sciences, University of Taipei, Taipei, Taiwan 3 Department of Life Sciences, National Chung Hsing University, Taichun, Taiwan 4 Department of Biology, Duke University, Durham, USA 5 Department of Botany, National Museum of Nature and Science, Tsukuba, Japan 6 Taiwan Forestry Research Institute, Taiwan

Several horizontal gene transfers (HGT) found in ferns are interpreted to significantly benefit their adaptation. As the recent advances of mitogenome sequencing in these plants, more HGT cases are discovered from these genomes. In the fern family Ophioglossaceae, we assessed mitogenome assemblies from all generic representatives, and confirmed numerous HGTs inside their mitogenomes. In the most extreme case, up to one third of mitogenome is HGT-originated. Newly compiled phylogenomic datasets revealed that these HGTs are derived from diverse donors, primarily root parasite angiosperms but also a few from ferns and lycophytes. To evaluate the functionality of these horizontally-transferred genes within the host mitogenomes, we generated transcriptomic data to examine their expression levels and RNA editing patterns. Our novel insights emphasize a unique and unusual evolutionary process by which ferns can acquire a substantial number of foreign genes from angiosperms through plant-to-plant HGTs.