背景回顾：Coconut is an important tropical oil and fruit crop whose evolutionary position renders it a fantastic species for the investigation of the evolution of monocot chromosomes and the subsequent differentiation of ancient plants. 

主要研究：Here, we report the assembly and annotation of reference-grade genomes of Cn. tall andCn. dwarf, whose genome sizes are 2.40 Gb and 2.39 Gb, respectively. 

结果1-高矮椰子分化：The comparative analysis reveals that the two coconut subspecies diverge about 2–8 Mya while the conserved Arecaceae-specific whole-genome duplication (ω WGD) occurs approximately 47–53 Mya. 

结果2-单子叶祖先染色体核型：It additionally allows us to reconstruct the ancestral karyotypes of the ten ancient monocot chromosomes and the evolutionary trajectories of the 16 modern coconut chromosomes. 

结果3-纤维含量：Fiber synthesis genes in Cn. tall, related to lignin and cellulose synthesis, are found at a higher copy number and expression level than dwarf coconuts. 

结果4-株高差异：Integrated multi-omics analysis reveals that the difference in coconut plant height is the result of altered gibberellin metabolism, with both the GA20ox copy number and a single-nucleotide change in the promoter together leading to the difference in plant height between Cn. tall and Cn. dwarf. 

结论：We provide high-quality coconut genomes and reveal the genetic basis of trait differences between two coconuts through multi-omics analysis. We also reveal that the selection of plant height has been targeted for the same gene for millions of years, not only in natural selection of ancient plant as illustrated in coconut, but also for artificial selection in cultivated crops such as rice and maize.

 摘 要 

椰子是一种重要的热带油料和水果作物，其系统发育地位使其成为研究祖先单子叶植物染色体演化及随后分化的理想物种。本文中，作者报道了高椰子和矮椰子的参考基因组，基因组大小分别为2.40Gb和2.39Gb。比较分析表明，这两个椰子亚种的分化时间约为两百万年到八百万年前，而保守的棕榈科特有全基因组复制事件ωWGD的发生时间约为四千七百万年到五千三百万年前。此外，作者重建了单子叶植物十条染色体的祖先核型以及现代椰子十六条染色体的演化轨迹。高椰子中与木质素和纤维素合成有关的纤维合成基因要比矮椰子中的具有更多的拷贝数以及更高的表达水平。结合多组学分析，作者发现椰子树高的差异是赤霉素代谢改变的结果，GA20ox拷贝数和启动子中单个核苷酸的改变共同导致了高矮种椰子之间的树高差异。本文中，作者报道了高质量的椰子基因组，并通过多组学分析揭示了两种椰子性状差异的遗传基础。作者还发现，对于植物树高性状的选择在数百万年来都是靶向的同一个基因，这不仅在椰子中所示的古老植物的自然选择，在水稻和玉米等栽培作物的人工选择中也是如此。