Pests, diseases, and aridity have shaped the genome of Corymbia citriodora

• Published in: Communications biology 2021-05, Vol.4 (1), p.537-13, Article 537
• Main Authors: Healey, Adam L., Shepherd, Mervyn, King, Graham J., Butler, Jakob B., Freeman, Jules S., Lee, David J., Potts, Brad M., Silva-Junior, Orzenil B., Baten, Abdul, Jenkins, Jerry, Shu, Shengqiang, Lovell, John T., Sreedasyam, Avinash, Grimwood, Jane, Furtado, Agnelo, Grattapaglia, Dario, Barry, Kerrie W., Hundley, Hope, Simmons, Blake A., Schmutz, Jeremy, Vaillancourt, René E., Henry, Robert J.
• Format: Article
• Language: English
• Subjects: 38/91; 45; 45/23; 631/449/2669; 706/1145; BASIC BIOLOGICAL SCIENCES; Biology; Biomedical and Life Sciences; Chromosome Mapping; Chromosome rearrangements; Chromosomes; Chromosomes, Plant - genetics; Comparative analysis; Corymbia; Corymbia citriodora; Drought; Essential oils; Forestry; Gene Duplication; Gene Rearrangement; Genome, Plant; Genomes; Growth rate; Life Sciences; Myrtaceae - genetics; Myrtaceae - growth & development; Myrtaceae - immunology; Pests; Plant evolution; Plant Proteins - genetics; Pulp; Synteny
• ISSN: 2399-3642; 2399-3642
• DOI: 10.1038/s42003-021-02009-0

Corymbia citriodora is a member of the predominantly Southern Hemisphere Myrtaceae family, which includes the eucalypts ( Eucalyptus , Corymbia and Angophora ; ~800 species). Corymbia is grown for timber, pulp and paper, and essential oils in Australia, South Africa, Asia, and Brazil, maintaining a high-growth rate under marginal conditions due to drought, poor-quality soil, and biotic stresses. To dissect the genetic basis of these desirable traits, we sequenced and assembled the 408 Mb genome of Corymbia citriodora , anchored into eleven chromosomes. Comparative analysis with Eucalyptus grandis reveals high synteny, although the two diverged approximately 60 million years ago and have different genome sizes (408 vs 641 Mb), with few large intra-chromosomal rearrangements. C. citriodora shares an ancient whole-genome duplication event with E. grandis but has undergone tandem gene family expansions related to terpene biosynthesis, innate pathogen resistance, and leaf wax formation, enabling their successful adaptation to biotic/abiotic stresses and arid conditions of the Australian continent. Healey and colleagues presented a reference sequence assembly of Corymbia citriodora (spotted gum), a tree which is crucial for timber, pulp, and paper, as well as carbon sequestration and essential oil production.