Poster Presentation International Plant Molecular Biology Conference 2024

Control of stem cell behavior by CLE-JINGASA signaling in the shoot apical meristem in Marchantia polymorpha (#123)

Go Takahashi 1 , Tomohiro Kiyosue 1 , Yuki Hirakawa 1
  1. Gakushuin University, Toshima-ku, TOKYO, Japan

In the flowering plant Arabidopsis thaliana, overall morphology of the shoot apical meristem (SAM) is relatively constant throughout its lifetime. In contrast, the SAM of the liverwort Marchantia polymorpha undergoes periodic bifurcation in which the single apical cell is thought to be duplicated within the stem cell zone (SCZ). We have previously shown that MpCLE2 peptide, the single ortholog of A. thaliana CLV3/CLE40 peptides, positively regulates the size of the SCZ and the apical cell number, via the leucine-rich repeat receptor-like kinases, MpCLV1 and MpCIK (Hirakawa et al., 2020; Takahashi et al., 2021). To identify target genes of MpCLE2 signaling, we performed an RNA-seq analysis using gain-of-function and loss-of-function alleles for MpCLE2 and its receptors. Among hundreds of DEGs, we found a NAC family transcription factor, namely MpJINGASA (MpJIN), whose expression level was dramatically decreased in gain-of-function alleles for MpCLE2. Knockout alleles for MpJIN (MpJIN-KO) showed slight increase in the SCZ size, indicating that MpJIN negatively regulates the SCZ size under the MpCLE2 signaling. In promoter-reporter analysis, MpJIN expression was associated with the periclinal cell division at the periphery of the SCZ, whereas faint MpJIN expression was found at the center of the SCZ. Consistently, the induction of MpJIN results in ectopic periclinal cell division in the SCZ. Collectively, our data suggest that MpJIN acts as a negative regulator of stem cell identity by inducing periclinal division at the periphery of the SCZ (Takahashi et al., 2023). We are analyzing the MpJIN expression dynamics during the dichotomous branching event.

  1. Hirakawa, Y., Fujimoto, T., Ishida, S., Uchida, N., Sawa, S., Kiyosue, T., Ishizaki, K., Nishihama, R., Kohchi, T., and Bowman, J.L. (2020). Induction of multichotomous branching by CLAVATA peptide in Marchantia polymorpha. Curr. Biol. 30, 3833–3840.e4.
  2. Takahashi, G., Betsuyaku, S., Okuzumi, N., Kiyosue, T., and Hirakawa, Y. (2021). An evolutionarily conserved coreceptor gene is essential for CLAVATA signaling in Marchantia polymorpha. Front. Plant Sci. 12, 657548.
  3. Takahashi, G., Kiyosue, T., & Hirakawa, Y. (2023). Control of stem cell behavior by CLE-JINGASA signaling in the shoot apical meristem in Marchantia polymorpha. Curr. Biol. 33(23), 5121–5131.e6.