The evolution of transporting tissues was an important innovation in terrestrial plants that allowed them to adapt to almost all nonaquatic environments. These tissues consist of water-conducting cells and food-conducting cells and bridge plant–soil and plant–air interfaces over long distances. The largest group of land plants, representing about 95% of all known plant species, is associated with morphologically complex transporting tissue in plants with a range of additional traits. Therefore, this entire clade was named tracheophytes, or vascular plants. However, some nonvascular plants possess conductive tissues that closely resemble vascular tissue in their organization, structure, and function. Recent molecular studies also point to a highly conserved toolbox of molecular regulators for transporting tissues. Here, we reflect on the distinguishing features of conductive and vascular tissues and their evolutionary history. Rather than sudden emergence of complex, vascular tissues, plant transporting tissues likely evolved gradually, building on pre-existing developmental mechanisms and genetic components. Improved knowledge of the intimate structure and developmental regulation of transporting tissues across the entire taxonomic breadth of extant plant lineages, combined with more comprehensive documentation of the fossil record of transporting tissues, is required for a full understanding of the evolutionary trajectory of transporting tissues.

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运输组织的深层起源和渐进演化：来自陆地植物的视角

运输组织的进化是陆生植物的一项重要创新，使它们能够适应几乎所有非水生环境。这些组织由水传导细胞和食物传导细胞组成，并在长距离上连接植物-土壤和植物-空气界面。最大的陆地植物群，约占所有已知植物物种的 95%，与具有一系列附加特征的植物中形态复杂的运输组织有关。因此，这整个进化枝被命名为气管植物或维管植物。然而，一些非维管植物的导电组织在组织、结构和功能上与维管组织非常相似。最近的分子研究还指出了一个高度保守的用于运输组织的分子调节剂工具箱。这里，我们反思导电和血管组织的显着特征及其进化历史。植物运输组织可能不是突然出现的复杂的维管组织，而是逐渐进化，建立在预先存在的发育机制和遗传成分的基础上。要全面了解运输组织的进化轨迹，需要提高对在现存植物谱系的整个分类范围内运输组织的紧密结构和发育调控的了解，以及对运输组织化石记录的更全面的记录。建立在预先存在的发育机制和遗传成分的基础上。要全面了解运输组织的进化轨迹，需要提高对在现存植物谱系的整个分类范围内运输组织的紧密结构和发育调控的了解，以及对运输组织化石记录的更全面的记录。建立在预先存在的发育机制和遗传成分的基础上。要全面了解运输组织的进化轨迹，需要提高对在现存植物谱系的整个分类范围内运输组织的紧密结构和发育调控的了解，以及对运输组织化石记录的更全面的记录。