A Transcriptome Atlas of Physcomitrella patens Provides Insights into the Evolution and Development of Land Plants
A Transcriptome Atlas of Physcomitrella patens Provides Insights into the Evolution and Development of Land Plants
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DOI：
10.1016/j.molp.2015.12.002
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发表时间：
2016-02-01
期刊：
影响因子：
27.5
通讯作者：
Becker, Joerg D.
中科院分区：
文献类型：
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作者：
Ortiz-Ramirez, Carlos;Hernandez-Coronado, Marcela;Becker, Joerg D.
识别支持新器官和组织系统进化的遗传机制是进化发育生物学的目标。被子植物和苔藓植物之间的比较功能遗传学研究可以定义那些导致发育创新的遗传变化。在这里，我们报告了转录组图谱的生成，涵盖了苔藓植物模型小立碗藓生命周期的大部分阶段，包括详细的孢子体发育进程。我们鉴定了一套全面的孢子体特异性转录因子，并发现其中许多基因在被子植物中具有同源物，在开花和芽分枝等发育过程中发挥作用。 PpTCP5转录因子的缺失会导致附着在单个刚毛上的多余孢子囊的发育，表明它对苔藓孢子体的分枝有负调节作用。鉴于 TCP 基因抑制被子植物的分支，我们认为这种活动是古老的。最后，通过比较小叶菜和拟南芥转录组，我们鉴定了尖端生长细胞中表达的转录因子的保守核心。我们确定了这些基因表达模式的修饰，这些修饰可以解释 P. patens 尖端生长细胞与拟南芥花粉管和根毛之间的发育差异。
Identifying the genetic mechanisms that underpin the evolution of new organ and tissue systems is an aim of evolutionary developmental biology. Comparative functional genetic studies between angiosperms and bryophytes can define those genetic changes that were responsible for developmental innovations. Here, we report the generation of a transcriptome atlas covering most phases in the life cycle of the model bryo-phyte Physcomitrella patens, including detailed sporophyte developmental progression. We identified a comprehensive set of sporophyte-specific transcription factors, and found that many of these genes have homologs in angiosperms that function in developmental processes such as flowering and shoot branching. Deletion of the PpTCP5 transcription factor results in development of supernumerary sporangia attached to a single seta, suggesting that it negatively regulates branching in the moss sporophyte. Given that TCP genes repress branching in angiosperms, we suggest that this activity is ancient. Finally, comparison of P. patens and Arabidopsis thaliana transcriptomes led us to the identification of a conserved core of transcription factors expressed in tip-growing cells. We identified modifications in the expression patterns of these genes that could account for developmental differences between P. patens tip-growing cells and A. thaliana pollen tubes and root hairs.