Biology subjects

Furuya, T.

Publications and source records attributed to Furuya, T..

4 recordsLinked to original sources

bioRxiv2024

Evolutionary conserved RLF, a plant cytochrome b5-like heme-binding protein, is essential for organ development in Marchantia polymorpha

In Arabidopsis thaliana, REDUCED LATERAL ROOT FORMATION (RLF), a cytochrome b5-like heme-binding domain (Cytb5-HBD) protein, is necessary for proper lateral root formation. Whereas the other Cytb5-HBD proteins in A. thaliana regulate different metabolic reactions, RLF is unique as it specifically regulates organ development. However, it remains unknown whether heme binding to RLF is necessary for its function, and whether RLF orthologs in different plant species also regulate organ development. We demonstrate that RLF binds to heme in vitro and that the two histidine residues, which are conserved among Cytb5-HBD, are crucial for both heme binding and its biological function in A. thaliana. In addition, MpRLF, a RLF ortholog in Marchantia polymorpha, rescues the lateral root formation phenotype of the A. thaliana rlf mutant. Mprlfge, the loss-of-function mutation in the MpRLF, resulted in delayed thallus growth and inhibited both gemma cup and antheridiophore formation. Transcriptome analysis using Mprlfge revealed that MpRLF affects several metabolic pathways. Our findings indicate that MpRLF is essential for vegetative and reproductive development in M. polymorpha, suggesting that the RLF-dependent redox reaction systems are evolutionarily conserved as crucial mechanisms for organ development across diverse plant species.

plant biology↗

bioRxiv2022

The bHLH transcription factor MpHYPNOS is a critical regulator of gemma dormancy in the liverwort Marchantia polymorpha.

O_LIDormancy is a key process employed by land plants to adapt to harsh terrestrial environments. The liverwort Marchantia polymorpha produces dormant propagules called gemmae for asexual reproduction. The plant hormone abscisic acid (ABA) plays important roles in regulating dormancy in both the seeds of flowering plants and the gemmae of M. polymorpha. C_LIO_LIBased on previous transcriptome analysis, we identified the basic helix-loop-helix transcription factor MpHYPNOS (MpHYP) as a key regulator of gemma dormancy. C_LIO_LIKnock-out mutants of MpHYP showed much higher germination rates of gemmae in gemma cups than ABA-related mutants, while the growth and development of these mutants resembled that of the wild type. Transient induction of MpHYP caused irreversible growth arrest of gemmae and thalli. Transcriptome and RT-qPCR analyses revealed that MpHYP represses the expression of cell cycle-related genes and induces ABA biosynthesis and ABA-responsive genes. Indeed, ABA levels increased in MpHYP overexpression lines and decreased in Mphyp knock-out lines. However, the growth arrest caused by MpHYP overexpression was not suppressed by a mutation in an ABA receptor gene. C_LIO_LIThese findings suggest that MpHYP regulates gemma dormancy and thallus growth mainly through the ABA-independent pathway, providing clues about ABA-dependent and independent regulation of dormancy in land plants. C_LI

plant biology↗

bioRxiv2021

VISUAL network analysis reveals the role of BEH3 as a stabilizer in the secondary vascular development in Arabidopsis

During secondary growth in plants, vascular stem cells located in the cambium continuously undergo self-renewal and differentiation throughout the lifetime. Recent cell-sorting technique enables to uncover transcriptional regulatory framework for cambial cells. However, the mechanisms underlying the robust control of vascular stem cells have not been understood yet. By coexpression network analysis using multiple transcriptome datasets of an ectopic vascular cell transdifferentiation system using Arabidopsis cotyledons, VISUAL, we newly identified a cambium-specific gene module from an alternative approach. The cambium gene list included a transcription factor BES1/BZR1 homolog 3 (BEH3), whose homolog BES1 is known to control vascular stem cell maintenance negatively. Interestingly, the vascular size of the beh3 mutants showed a large variation, implying the role of BEH3 as a stabilizer. BEH3 almost lost the transcriptional repressor activity and functioned antagonistically with other BES/BZR members via competitive binding to the same motif BRRE. Indeed, mathematical modeling suggests that the competitive relationship among BES/BZRs leads to the robust regulation of vascular stem cells.

developmental biology↗

bioRxiv2020

GSK3 activity is a cell fate switch that balances the ratio of vascular cell type

The phloem transports photosynthetic assimilates and signalling molecules. It mainly consists of sieve elements (SEs), which act as "highways" for transport, and companion cells (CCs), which serve as "gates" to load/unload cargos. Though SEs and CCs function together, it remains unknown what determines the ratio of SE/CC in the phloem. In this study, we develop a novel culture system for CC differentiation named VISUAL-CC, which reconstitutes the SE-CC complex formation. Comparative expression analysis in VISUAL-CC reveals that SE and CC differentiation tends to show negative correlation, while total phloem differentiation is unchanged. This varying SE/CC ratio is largely dependent on GSK3 kinase activity. Indeed, gsk3 hextuple mutants possess much more SEs and less CCs in planta. Conversely, gsk3 gain-of-function mutants induced by phloem-specific promoter partially increased the CC ratio. Taken together, GSK3 activity appears to function as a cell fate switch in the phloem, thereby balancing the SE/CC ratio.

plant biology↗