Tillandsia Genome sequencing and assembly. Tillandsia

Identifying the evolutionary processes that drive trait evolution and diversification is central to understanding plant diversity and evolution. The subgenus Tillandsia (Bromeliaceae) belongs to one of the fastest radiating clades in the plant kingdom and is characterised by the repeated evolution of the water-conserving Crassulacean Acid Metabolism (CAM). CAM has evolved independently across many plant families and over short timescales, despite having a complex genetic basis. By producing the first high-quality de novo genome assemblies of a species pair representing a recent CAM/C3 shift, we were able to investigate genomic drivers of trait evolution and diversification in Tillandsia. Combining genome-wide investigations of synteny, Te dynamics, sequence evolution, gene family evolution and differential gene expression, we highlighted the crucial role of rapid gene family expansion and transposable element activity at differentially expressed genes in fuelling CAM/C3 shifts in this vast plant radiation.

解析驱动性状演化与物种多样化的进化过程，是理解植物多样性与演化机制的核心所在。铁兰亚属（凤梨科，Bromeliaceae）隶属于植物界辐射演化最快的支系之一，其典型特征为保水性景天酸代谢（Crassulacean Acid Metabolism, CAM）的反复演化。尽管景天酸代谢具有复杂的遗传基础，却能在众多植物类群中独立演化，且发生于较短的演化时间尺度内。本研究首次对一对代表近期发生CAM/C3光合途径转换的物种开展高质量从头基因组组装，借此得以解析铁兰属植物性状演化与物种多样化的基因组驱动因素。本研究整合全基因组共线性分析、转座因子（Transposable Element, TE）动态变化分析、序列演化分析、基因家族演化分析与差异基因表达分析，揭示了快速基因家族扩张以及差异表达基因区域的转座因子活性，在推动这一庞大植物辐射类群的CAM/C3光合途径转换中发挥的关键作用。