Department of Botany, St. Petersburg State University, Universitetskaya Nab. 7/9, 190034 Saint Petersburg, Russia.
Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376 Saint Petersburg, Russia.
Int J Mol Sci. 2021 Apr 16;22(8):4139. doi: 10.3390/ijms22084139.
Mounting evidence from genomic and transcriptomic studies suggests that most genetic networks regulating the morphogenesis of land plant sporophytes were co-opted and modified from those already present in streptophyte algae and gametophytes of bryophytes . However, thus far, no candidate genes have been identified that could be responsible for "planation", a conversion from a three-dimensional to a two-dimensional growth pattern. According to the telome theory, "planation" was required for the genesis of the leaf blade in the course of leaf evolution. The key transcription factors responsible for leaf blade development in angiosperms are YABBY proteins, which until recently were thought to be unique for seed plants. Yet, identification of a YABBY homologue in a green alga and the recent findings of YABBY homologues in lycophytes and hornworts suggest that YABBY proteins were already present in the last common ancestor of land plants. Thus, these transcriptional factors could have been involved in "planation", which fosters our understanding of the origin of leaves. Here, we summarise the current data on functions of YABBY proteins in the vegetative and reproductive development of diverse angiosperms and gymnosperms as well as in the development of lycophytes. Furthermore, we discuss a putative role of YABBY proteins in the genesis of multicellular shoot apical meristems and in the evolution of leaves in early divergent terrestrial plants.
越来越多的基因组和转录组研究证据表明，调控陆地植物孢子体形态发生的大多数遗传网络是从石松类藻类和苔藓类配子体中已有的遗传网络中共同选择和改造而来的。然而，到目前为止，还没有发现可能负责“平面化”的候选基因，“平面化”是从三维到二维生长模式的转变。根据端粒学说，“平面化”是叶片进化过程中叶片发生的必要条件。在被子植物中，叶片发育的关键转录因子是 YABBY 蛋白，直到最近，人们还认为 YABBY 蛋白是种子植物所特有的。然而，在绿藻中鉴定出 YABBY 同源物，以及最近在石松类和角苔类中发现 YABBY 同源物，表明 YABBY 蛋白已经存在于陆地植物的最后共同祖先中。因此，这些转录因子可能参与了“平面化”，这有助于我们理解叶子的起源。在这里，我们总结了 YABBY 蛋白在不同被子植物和裸子植物的营养和生殖发育以及石松类植物发育中的功能的最新数据。此外，我们还讨论了 YABBY 蛋白在多细胞茎尖分生组织发生和早期陆地植物叶片进化中的可能作用。
