We study fundamental mechanisms in plant evolution and development. We particularly focus on the shoot apical meristem formed in gametophyte generation in the liverwort Marchantia polymorpha. Some of our past research papers are listed below. To see the publication list please see here.
Regulation of periclinal cell division in stem cells by JINGASA transcription factor, a conserved mechanism in land plant meristems (Takahashi 2023)
In a transcriptome analysis using MpCLE2 overexpression lines and receptor-KO lines, we identified several differentially expressed transcription factor genes, including JINGASA(MpJIN), the sole member of JIN/FEZ subfamily of NAC domain TF in Marchantia. MpJIN is highly expressed at the periphery of the stem cell zone and promotes periclinal division. The expression level of MpJIN was varied among cells in the stem cell zone. From the observation of this marker, we found dynamic change of gene expression at the branching event: loss and de novo formation of MpJIN-negative cells during dichoutomous branching in Marchantia.
A hypothesis on the evolution of CLE peptide signaling and shoot apical meristems in land plants (Hirakawa 2022)
An opinion paper about the evolution of CLE peptide signaling. This paper proposes that stem-cell-promoting CLE peptide signaling, such as Marchantia MpCLE2 and Arabidopsis CLE40, may be a conserved mechanism in the shoot apical meristems in gametophyte and sporophyte generations of land plants. In contrast, canonical Arabidopsis CLV3 signaling may be a derived condition evolving after gene duplication in the flowering plant lineage.
Evolution of meristem zonation by CLE gene duplication in land plants | Nat Plants (featured on the cover)
Conservation of CLE peptide receptors between Arabidopsis and Marchantia (Takahashi et al. 2021)
Marchantia has a single homolog of Arabidopsis CIK/CLERK/NIK coreceptors. The Marchantia gene, MpCIK, is essential for MpCLE2 signaling in meristem and gemma cup development. Thus, the ligand-receptor pairs seem broadly conserved in land plants.
Increase of stem cells by MpCLE2 peptide signaling in Marchantia gametophyte (Hirakawa et al. 2020)
This study shows MpCLE2 is a positive regulator of the stem cell population size in the shoot apical meristem of Marchantia gametophyte. Supernumerary branching can be induced by MpCLE2 peptide treatment. The function of MpCLE2 is opposite to that of CLV3 in the shoot apical meristem of Arabidopsis sporophyte.
Induction of Multichotomous Branching by CLAVATA Peptide in Marchantia polymorpha | Curr Biol
Suppression of cell proliferation by MpCLE1 peptide signaling in Marchantia gametophyte (Hirakawa et al. 2019)
Marchantia has two CLE genes, MpCLE1 and MpCLE2. This study shows MpCLE1, the close homolog of Arabidopsis TDIF/CLE41/CLE44, acts as a negative regulator of cell proliferation in the shoot apical meristem of Marchantia gametophyte.
Funding
Japan Society for the Promotion of Science (JSPS)
Takeda Science Foundation