Induction of non-gametic embryo derived from the synergid cell.

2022 Fiscal Year Final Research Report

• Project Area: Remodeling Plant Reproduction System by Cell Fate Manipulations.
• Project/Area Number: 20H05781
• Research Category: Grant-in-Aid for Transformative Research Areas (B)
• Allocation Type: Single-year Grants
• Review Section: Transformative Research Areas, Section (III)
• Research Institution: Yokohama City University
• Principal Investigator: Maruyama Daisuke 横浜市立大学, 木原生物学研究所, 准教授 (80724111)
• Project Period (FY): 2020-10-02 – 2023-03-31
• Keywords: 重複受精 / 花粉管 / 助細胞 / 多胚性種子 / 助細胞胚 / 助細胞胚乳融合

Outline of Final Research Achievements

In flowering plants, two female gametophytic accessory cells play pivotal roles in pollen tube guidance and double fertilization. In most species, the synergid cells are thought to be eliminated after double fertilization, however, a few exceptions reported polyembryony due to the production of synergid-derived embryo. I thus tried to generate polyembryonic Arabidopsis by preventing synergid cell death and ectopic expression of transcription factor related to the somatic embryogenesis. Although polyembryony was not observed in the synergid elimination mutants expressing embryo-inducible RKD1 transcription factor in the synergid cell, this study illuminated next step toward formation of the synergid-derived embryo and brought novel insight on molecular mechanism of non-gametic cell fusion in plants that occurs in inactivating synergid cell after double fertilization.

Free Research Field

植物生殖学

Academic Significance and Societal Importance of the Research Achievements

卵細胞の姉妹細胞にあたる助細胞から胚を作出することは、近年需要が高まっているDouble Haploid（DH）技術、すなわち、半数体を介して全ての遺伝子をホモ接合とする形質固定法の開発に貢献する。本研究結果は今後の助細胞胚の作出に役立つと期待される。また、助細胞不活性化のツールとしての位置づけであった助細胞と胚乳の細胞融合機構については、融合制御因子であるCTL17の同定や機能解析を通じて多様な知見が得られた。この結果は被子植物の体づくりの可塑性を新たな視点から考えさせるような研究に繋がる発見といえる。