Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.
University of the Chinese Academy of Sciences, Beijing 100049, China.
J Exp Bot. 2024 Jul 10;75(13):3946-3958. doi: 10.1093/jxb/erae176.
Plant life history is determined by two transitions, germination and flowering time, in which the phosphatidylethanolamine-binding proteins (PEBPs) FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1) play key regulatory roles. Compared with the highly conserved TFL1-like genes, FT-like genes vary significantly in copy numbers in gymnosperms, and monocots within the angiosperms, while sporadic duplications can be observed in eudicots. Here, via a systematic analysis of the PEBPs in angiosperms with a special focus on 12 representative species featuring high-quality genomes in the order Lamiales, we identified a successive lineage-specific but systematic expansion of FT-like genes in the families of core Lamiales. The first expansion event generated FT1-like genes mainly via a core Lamiales-specific whole-genome duplication (cL-WGD), while a likely random duplication produced the FT2-like genes in the lineages containing Scrophulariaceae and the rest of the core Lamiales. Both FT1- and FT2-like genes were further amplified tandemly in some families. These expanded FT-like genes featured highly diverged expression patterns and structural variation, indicating functional diversification. Intriguingly, some core Lamiales contained the relict MOTHER OF FT AND TFL1 like 2 (MFT2) that probably expanded in the common ancestor of angiosperms. Our data showcase the highly dynamic lineage-specific expansion of the FT-like genes, and thus provide important and fresh evolutionary insights into the gene regulatory network underpinning flowering time diversity in Lamiales and, more generally, in angiosperms.
植物的生活史由两个转变决定，即萌发和开花时间，在此过程中，磷脂乙醇胺结合蛋白（PEBP）中的开花时间基因（FT）和终端花 1 基因（TFL1）发挥着关键的调节作用。与高度保守的 TFL1 类似基因相比，在裸子植物和单子叶植物中的被子植物中，FT 类似基因的拷贝数变化显著，而在真双子叶植物中则可以观察到零星的重复。在这里，我们通过对被子植物中 PEBPs 的系统分析，特别关注了 12 个具有 Lamiales 目中高质量基因组的代表性物种，鉴定出 FT 类似基因在核心 Lamiales 科中的连续谱系特异性但系统的扩张。第一个扩张事件主要通过核心 Lamiales 特异性全基因组复制（cL-WGD）产生了 FT1 类似基因，而在包含玄参科和其他核心 Lamiales 的谱系中，可能是随机复制产生了 FT2 类似基因。FT1 和 FT2 类似基因在一些科中进一步串联扩增。这些扩张的 FT 类似基因具有高度分化的表达模式和结构变异，表明功能多样化。有趣的是，一些核心 Lamiales 包含了可能在被子植物共同祖先中扩张的 MOTHER OF FT AND TFL1 like 2（MFT2）。我们的数据展示了 FT 类似基因的高度动态谱系特异性扩张，为 Lamiales 中开花时间多样性的基因调控网络提供了重要的、全新的进化见解，更广泛地说，为被子植物提供了重要的、全新的进化见解。
