Takanashi Sota, Imamura Yuto, Ouchi Haruki, Sato Shoichi, Otani Masahiro, Nakano Masaru
Graduate School of Science and Technology, Niigata University.
Faculty of Agriculture, Niigata University.
Plant Biotechnol (Tokyo). 2025 Jun 25;42(2):155-161. doi: 10.5511/plantbiotechnology.25.0225a.
For ornamental plants, inflorescence architecture is one of the most important traits to determine their commercial values. However, molecular mechanisms of inflorescence architecture determination have not yet been fully elucidated. (), which encodes a plant-specific transcriptional factor, has been shown to play a key role in the switch from vegetative to reproductive phases. Recent studies have demonstrated that LFY is involved not only in floral meristem induction but also in inflorescence architecture determination. spp., which belong to the family Liliaceae, show two different types of inflorescence architecture: . produces both apical and lateral flowers, whereas . produces only apical flowers. In the present study, we isolated -homologous genes from . and . (designated as and , respectively) and analyze their functions and expression patterns as a first step toward elucidation of molecular mechanisms of inflorescence architecture determination in spp. Alignment analysis based on amino acid sequences showed that both ThirLFY and TforLFY have functional motifs of LFY, and only three amino acid differences are found between them. Transgenic plants overexpressing or showed early flowering and production of secondary inflorescences, and no functional differences were observed between ThirLFY and TforLFY. hybridization analysis showed that was expressed in both apical and lateral buds of . , whereas was only expressed in apical buds of . . Thus, two different types of inflorescence architecture in spp. may be caused by different expression patterns of -homologous genes.
对于观赏植物而言，花序结构是决定其商业价值的最重要性状之一。然而，花序结构决定的分子机制尚未完全阐明。LFY基因编码一种植物特异性转录因子，已被证明在从营养生长阶段向生殖生长阶段的转变中起关键作用。最近的研究表明，LFY不仅参与花分生组织的诱导，还参与花序结构的决定。百合科的郁金香属植物有两种不同类型的花序结构：郁金香既产生顶花也产生侧花，而福斯特郁金香只产生顶花。在本研究中，我们从郁金香和福斯特郁金香中分离出LFY同源基因（分别命名为ThirLFY和TforLFY），并分析它们的功能和表达模式，这是阐明郁金香属植物花序结构决定分子机制的第一步。基于氨基酸序列的比对分析表明，ThirLFY和TforLFY都具有LFY的功能基序，且它们之间仅发现三个氨基酸差异。过表达ThirLFY或TforLFY的转基因郁金香植物表现出早花并产生二级花序，且未观察到ThirLFY和TforLFY之间存在功能差异。原位杂交分析表明，ThirLFY在郁金香的顶芽和侧芽中均有表达，而TforLFY仅在郁金香的顶芽中表达。因此，郁金香属植物中两种不同类型的花序结构可能是由LFY同源基因的不同表达模式引起的。
