Plastomes of Sonchus (Asteraceae) endemic to the Atlantic Madeira archipelago: Genome structure, comparative analysis, and phylogenetic relationships

• Published in: PloS one Vol. 18; no. 6; p. e0287523
• Main Authors: Kim, Hye-Been, Lee, Dong-Geol, Kim, Seung-Chul
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22-06-2023; Public Library of Science (PLoS)
• Subjects: Adaptive radiation; Analysis; Archipelagoes; Asteraceae; Auroral kilometric radiation; Biology and Life Sciences; Chloroplasts; Coastal zone; Colonization; Comparative analysis; Compositae; Computer and Information Sciences; Diversification; Earth Sciences; Engineering and Technology; Genetic aspects; Genetic testing; Genomes; Identification and classification; Islands; Mutation; Mutation hot spots; People and places; Phylogenetics; Phylogeny; Plastomes; Portugal; Radiation; Ribosomal DNA; Shrubs; Sonchus; Sonchus - genetics; Taxa; Wood; Portugal; South Korea; Desertas; New Zealand; Macaronesia; Canary Islands; Cape Verde Islands; Morocco; Spain
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0287523

The woody Sonchus alliance, a spectacular example of adaptive radiation with six genera and approximately 31 species, is found exclusively on three Macaronesian Islands (Madeira, Canaries, and Cape Verdes) in the Atlantic Ocean. Four of the Sonchus taxa are restricted to Madeira, including shrubs and small trees at higher elevations (S. fruticosus and S. pinnatus), and caudex perennials in the lower coastal areas (S. ustulatus subsp. maderensis and S. ustulatus subsp. ustulatus). The Madeiran Sonchus stemmed from a single colonization event that originated from the Canaries < 3 million years ago. However, the plastome evolution and species relationships remains insufficiently explored. We therefore assembled and characterized the plastomes of four Sonchus taxa from Madeira and conducted a phylogenomic analysis. We found highly conserved plastome sequences among the taxa, further supporting a single and recent origin. We also found highly conserved plastomes among the cosmopolitan weedy Sonchus, Macaronesian Sonchus in the Atlantic, and Juan Fernández Islands Dendroseris in the Pacific. Furthermore, we identified four mutation hotspot regions (trnK-rps16, petN-psbM, ndhF-Ψycf1, and ycf1) and simple sequence repeat motifs. This study strongly supports the monophyly of Madeiran Sonchus. However, its relationship with the remaining woody Sonchus alliance from the Canary Islands requires further investigation.