2025-06-20 東京大学
植物ステロイドホルモンによる花粉管ガイダンスの向上
<関連情報>
- https://www.s.u-tokyo.ac.jp/ja/press/10833/
- https://www.cell.com/cell-reports/fulltext/S2211-1247(25)00586-8
雄性生殖組織と雌性生殖組織における遺伝子発現の協調による花粉管誘導の促進 Brassinosteroids promote pollen tube guidance by coordinating gene expression in male and female reproductive tissues
Kumi Matsuura-Tokita∙ Takamasa Suzuki ∙ Yusuke Kimata ∙ … ∙ Hitoshi Sakakibara, ∙ Akihiko Nakano ∙ Tetsuya Higashiyama
Cell Reports Published:June 19, 2025
DOI:https://doi.org/10.1016/j.celrep.2025.115815
Highlights
- Reproductive tissues of male and female Arabidopsis thaliana contain BL/CS
- BL promotes transcription of genes involved in pollen tube capacitation and guidance
- BL biosynthesis in pollen tubes and pistils is crucial for guidance
- Our study suggests steroid hormones have evolutionarily conserved roles in reproduction
Summary
Hormones play an essential role in the survival and maintenance of homeostasis. Steroid hormones are structurally and evolutionarily conserved across animals, insects, and plants. Brassinosteroids (BRs) are plant steroid hormones originally isolated from pollen grains. However, the molecular roles of BRs in plant reproduction remain unclear. Here, we show that biologically active BRs, brassinolide (BL) and castasterone (CS), are detected in pistils and accumulate in the pollen grains of Arabidopsis thaliana. In vitro incubation with BL promotes pollen tube capacitation and attraction to ovules. Furthermore, BL treatment elevates the expression of various reproductive genes in pollen tubes and ovules. Additionally, mutant ovules defective in BRI1 signaling show decreased guidance rates and abnormal development of the filiform apparatus in synergid cells. Overall, this study characterizes the molecular functions of both BL and CS in promoting pollen tube guidance by regulating gene expression in male and female reproductive tissues.
