Lucibelli Francesca, Carfora Angela, Becker Annette, Ehlers Katrin, Aceto Serena
Department of Biology, University of Naples Federico II, Napoli, Italy.
Fachbereich 08 Biologie und Chemie, Institute of Botany, Justus-Liebig-University, Giessen, Germany.
BMC Plant Biol. 2025 Jul 8;25(1):889. doi: 10.1186/s12870-025-06936-6.
Orchids are known for their extraordinarily diversified floral structures and evolutionary adaptations. The study of transcription factor genes, such as the gene , is crucial for understanding the molecular mechanisms underlying orchid development and evolution. This study aims to elucidate the evolutionary dynamics and expression patterns of genes across orchid subfamilies.
Through genomic and transcriptomic analyses, we identified 25 full-length genes in orchids, with two paralogs ( and -like genes) observed in Epidendroideae, Orchidoideae, Cypripedioideae, and Vanilloideae, while the most ancestral Apostasioideae retained a single-copy gene. In addition to the functional , genomic features reveal the presence of a pseudogene within Apostasioideae. Evolutionary analyses revealed relaxed selection pressures acting on orchid paralogs. Sequence comparison and expression analyses uncovered potential pseudogenization events affecting paralogs of Vanilloideae and Cypripedioideae, while in the most recent subfamily Epidendroideae, differential expression of in inner perianth tissues suggests the possible acquisition of a new function in the development of the lip callus.
Our study provides insights into the evolutionary trajectory of genes in orchids. The relaxed selection on paralogs might be related to pseudogenization or functional divergence. Pseudogenization of in most ancestral orchids and possible neofunctionalization in Epidendroideae indicate a dynamic evolutionary process shaping the functional repertoire of genes. These findings contribute to our understanding of the genetic basis of orchid diversity and evolution, with implications for future studies on the role of transcription factors in plant development and adaptation.
The online version contains supplementary material available at 10.1186/s12870-025-06936-6.
兰花以其极其多样化的花部结构和进化适应性而闻名。对转录因子基因（如 基因）的研究对于理解兰花发育和进化的分子机制至关重要。本研究旨在阐明兰花亚科中 基因的进化动态和表达模式。
通过基因组和转录组分析，我们在兰花中鉴定出25个全长 基因，在树兰亚科、红门兰亚科、杓兰亚科和香荚兰亚科中观察到两个旁系同源基因（ 和 -样基因），而最原始的拟兰亚科保留了一个单拷贝基因。除了功能性 基因外，基因组特征还揭示了拟兰亚科中存在一个 假基因。进化分析表明，作用于兰花 旁系同源基因的选择压力有所放松。序列比较和表达分析发现，影响香荚兰亚科和杓兰亚科 旁系同源基因的潜在假基因化事件，而在最新的树兰亚科中， 在内轮花被组织中的差异表达表明其可能在唇瓣胼胝体发育中获得了新功能。
我们的研究为兰花中 基因的进化轨迹提供了见解。对 旁系同源基因的选择压力放松可能与假基因化或功能分化有关。大多数原始兰花中 的假基因化以及树兰亚科中可能的新功能化表明了一个塑造 基因功能库的动态进化过程。这些发现有助于我们理解兰花多样性和进化的遗传基础，对未来转录因子在植物发育和适应中的作用研究具有启示意义。
在线版本包含可在10.1186/s12870-025-06936-6获取的补充材料。
