HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA.
University of Queensland/QAAFI, Brisbane, QLD, Australia.
Commun Biol. 2021 May 10;4(1):537. 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.
柠檬桉是南半球桃金娘科（主要包含桉树属、柠檬桉属和蓝桉属；约 800 种）的一个成员。柠檬桉在澳大利亚、南非、亚洲和巴西因其木材、纸浆和造纸以及精油而被广泛种植，其在干旱、土壤质量差和生物胁迫等边缘条件下仍能保持较高的生长速度。为了剖析这些理想特性的遗传基础，我们对柠檬桉的 408Mb 基因组进行了测序和组装，并将其锚定到十一条染色体上。与大果桉的比较分析显示出高度的同线性，尽管这两个物种大约在 6000 万年前就已经分化，并且具有不同的基因组大小（408Mb 对 641Mb），但很少有大的染色体内重排。柠檬桉与大果桉共享一个古老的全基因组复制事件，但经历了与萜烯生物合成、先天病原体抗性和叶蜡形成相关的串联基因家族扩张，使它们能够成功适应澳大利亚大陆的生物/非生物胁迫和干旱条件。
