Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany.
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
New Phytol. 2019 May;222(3):1638-1651. doi: 10.1111/nph.15732. Epub 2019 Mar 12.
The Brassicaceae family comprises c. 4000 species including economically important crops and the model plant Arabidopsis thaliana. Despite their importance, the relationships among major lineages in the family remain unresolved, hampering comparative research. Here, we inferred a Brassicaceae phylogeny using newly generated targeted enrichment sequence data of 1827 exons (> 940 000 bases) representing 63 species, as well as sequenced genome data of 16 species, together representing 50 of the 52 currently recognized Brassicaceae tribes. A third of the samples were derived from herbarium material, facilitating broad taxonomic coverage of the family. Six major clades formed successive sister groups to the rest of Brassicaceae. We also recovered strong support for novel relationships among tribes, and resolved the position of 16 taxa previously not assigned to a tribe. The broad utility of these phylogenetic results is illustrated through a comparative investigation of genome-wide expression signatures that distinguish simple from complex leaves in Brassicaceae. Our study provides an easily extendable dataset for further advances in Brassicaceae systematics and a timely higher-level phylogenetic framework for a wide range of comparative studies of multiple traits in an intensively investigated group of plants.
十字花科包含约 4000 个物种，包括经济上重要的作物和模式植物拟南芥。尽管它们很重要，但该科主要谱系之间的关系仍未解决，这阻碍了比较研究。在这里，我们使用新生成的 1827 个外显子（>940000 个碱基）的靶向富集序列数据，以及 16 个物种的测序基因组数据，代表了目前公认的 52 个十字花科族中的 50 个，推断了十字花科的系统发育。三分之一的样本来自植物标本，促进了对该科的广泛分类覆盖。六个主要分支形成了与其余十字花科连续的姐妹群。我们还恢复了在族间具有很强支持力的新关系，并解决了以前未分配给一个族的 16 个分类群的位置。通过对区分十字花科简单叶和复杂叶的全基因组表达特征进行比较研究，展示了这些系统发育结果的广泛应用。我们的研究为进一步推进十字花科系统学提供了一个易于扩展的数据集，并为广泛研究一组经过深入研究的植物的多种性状提供了一个及时的高级系统发育框架。
