TAKATSUKA Hirotomo
| Faculty Division of Natural Sciences Research Group of Biological Sciences | Associate Professor |
Last Updated :2025/11/27
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https://researchmap.jp/h-takatsuka/avatar.jpgName (Japanese)
TakatsukaName (Kana)
Hirotomo
Research Areas
Research History
- Apr. 2025 - Present, Nara Women's University, 准教授
- Oct. 2022 - Present, 科学技術振興機構 さきがけ研究者
- Nov. 2019 - Mar. 2025, Kanazawa University, Institute of Science and Engineering, 助教
- Nov. 2019 - Mar. 2024, 文部科学省 卓越研究員
- Apr. 2018 - Oct. 2019, Nara Institute of Science and Technology, 先端科学技術研究科・バイオサイエンス領域, 助教
- Apr. 2016 - Mar. 2018, Nara Institute of Science and Technology, Graduate School of Biological Sciences, 助教
Media Coverage
■Ⅱ．研究活動実績
Published Papers
- Refereed, Biophysics and Physicobiology, Biophysical Society of Japan, Cytoskeleton as a generator of characteristic physical properties of plant cells: ‘cell wall,’ ‘large vacuole,’ and ‘cytoplasmic streaming’, Amari Toshiki; Noriko Nagata; Motoki Tominaga; Hirotomo Takatsuka, Jun. 2025, Scientific journal, 10.2142/biophysico.bppb-v22.0013
- Refereed, Plant Biotechnology, Japanese Society for Plant Cell and Molecular Biology, Whole-mount immunostaining that avoids cross-reaction between antibodies from different host species for simultaneous visualization of actin filaments and microtubules, Toshiki Amari; Natsu Higashinaka; Masaki Ito; Hirotomo Takatsuka, 24 Dec. 2024, Scientific journal, 10.5511/plantbiotechnology.24.1103a
- Refereed, Plant signaling & behavior, Cytokinin signaling is involved in root hair elongation in response to phosphate starvation., Hirotomo Takatsuka; Toshiki Amari; Masaaki Umeda, Root hair, single-celled tubular structures originating from the epidermis, plays a vital role in the uptake of nutrients from the soil by increasing the root surface area. Therefore, optimizing root hair growth is crucial for plants to survive in fluctuating environments. Root hair length is determined by the action of various plant hormones, among which the roles of auxin and ethylene have been extensively studied. However, evidence for the involvement of cytokinins has remained elusive. We recently reported that the cytokinin-activated B-type response regulators, ARABIDOPSIS RESPONSE REGULATOR 1 (ARR1) and ARR12 directly upregulate the expression of ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4), which encodes a key transcription factor that controls root hair elongation. However, depending on the nutrient availability, it is unknown whether the ARR1/12-RSL4 pathway controls root hair elongation. This study shows that phosphate deficiency induced the expression of RSL4 and increased the root hair length through ARR1/12, though the transcript and protein levels of ARR1/12 did not change. These results indicate that cytokinins, together with other hormones, regulate root hair growth under phosphate starvation conditions., 24 Jan. 2024, 19, 1, 2305030, 2305030, Scientific journal, True, 10.1080/15592324.2024.2305030
- Refereed, Plant Biotechnology, Japanese Society for Plant Cell and Molecular Biology, MYB3R-mediated and cell cycle-dependent transcriptional regulation of a tobacco ortholog of <i>SCARECROW-LIKE28</i> in synchronized cultures of BY-2 cells, Keito Mineta; Junya Hirota; Kesuke Yamada; Takashi Itoh; Poyu Chen; Hidekazu Iwakawa; Hirotomo Takatsuka; Yuji Nomoto; Masaki Ito, 25 Dec. 2023, 40, 4, 353, 359, Scientific journal, 10.5511/plantbiotechnology.23.0515a
- Refereed, Communications Biology, Springer Science and Business Media LLC, The canonical E2Fs together with RETINOBLASTOMA-RELATED are required to establish quiescence during plant development, Magdolna Gombos; Cécile Raynaud; Yuji Nomoto; Eszter Molnár; Rim Brik-Chaouche; Hirotomo Takatsuka; Ahmad Zaki; Dóra Bernula; David Latrasse; Keito Mineta; Fruzsina Nagy; Xiaoning He; Hidekazu Iwakawa; Erika Őszi; Jing An; Takamasa Suzuki; Csaba Papdi; Clara Bergis; Moussa Benhamed; László Bögre; Masaki Ito; Zoltán Magyar, Abstract
Maintaining stable and transient quiescence in differentiated and stem cells, respectively, requires repression of the cell cycle. The plant RETINOBLASTOMA-RELATED (RBR) has been implicated in stem cell maintenance, presumably by forming repressor complexes with E2F transcription factors. Surprisingly we find that mutations in all three canonical E2Fs do not hinder the cell cycle, but similarly to RBR silencing, result in hyperplasia. Contrary to the growth arrest that occurs when exit from proliferation to differentiation is inhibited upon RBR silencing, the e2fabc mutant develops enlarged organs with supernumerary stem and differentiated cells as quiescence is compromised. While E2F, RBR and the M-phase regulatory MYB3Rs are part of the DREAM repressor complexes, and recruited to overlapping groups of targets, they regulate distinct sets of genes. Only the loss of E2Fs but not the MYB3Rs interferes with quiescence, which might be due to the ability of E2Fs to control both G1-S and some key G2-M targets. We conclude that collectively the three canonical E2Fs in complex with RBR have central roles in establishing cellular quiescence during organ development, leading to enhanced plant growth., 04 Sep. 2023, 6, 1, Scientific journal, 10.1038/s42003-023-05259-2 - Refereed, Plant And Cell Physiology, Oxford University Press (OUP), Arabidopsis thaliana Subclass I ACTIN DEPOLYMERIZING FACTORs Regulate Nuclear Organization and Gene Expression, Tomoko Matsumoto; Takumi Higaki; Hirotomo Takatsuka; Natsumaro Kutsuna; Yoshiyuki Ogata; Seiichiro Hasezawa; Masaaki Umeda; Noriko Inada, Abstract
ACTIN DEPOLYMERIZING FACTOR (ADF) is a conserved protein that regulates the organization and dynamics of actin microfilaments. Eleven ADFs in the Arabidopsis thaliana genome are grouped into four subclasses, and subclass I ADFs, ADF1–4, are all expressed throughout the plant. Previously, we showed that subclass I ADFs function in the regulation of the response against powdery mildew fungus as well as in the regulation of cell size and endoreplication. Here, we report a new role of subclass I ADFs in the regulation of nuclear organization and gene expression. Through microscopic observation of epidermal cells in mature leaves, we found that the size of chromocenters in both adf4 and transgenic lines where expression of subclass I ADFs is downregulated (ADF1-4Ri) was reduced compared with that of wild-type Col-0. Arabidopsis thaliana possesses eight ACTIN (ACT) genes, among which ACT2, −7 and −8 are expressed in vegetative organs. The chromocenter size in act7, but not in the act2/8 double mutant, was enlarged compared with that in Col-0. Microarray analysis revealed that 1,818 genes were differentially expressed in adf4 and ADF1-4Ri. In particular, expression of 22 nucleotide-binding leucine-rich repeat genes, which are involved in effector-triggered plant immunity, was reduced in adf4 and ADF1-4Ri. qRT-PCR confirmed the altered expressions shown with microarray analysis. Overall, these results suggest that ADF regulates various aspects of plant physiology through its role in regulation of nuclear organization and gene expression. The mechanism how ADF and ACT regulate nuclear organization and gene expression is discussed., 18 Aug. 2023, Scientific journal, 10.1093/pcp/pcad092 - Refereed, Journal of Experimental Botany, Oxford University Press (OUP), Cytokinin signaling promotes root hair growth by directly regulating RSL4 expression, Hirotomo Takatsuka; Anna Sasaki; Naoki Takahashi; Michitaro Shibata; Keiko Sugimoto; Maho Tanaka; Motoaki Seki; Masaaki Umeda, Abstract
Root hairs are single-celled tubular structures produced from the epidermis, which play an essential role in water and nutrient uptake from the soil. Therefore, root hair formation and elongation are controlled not only by developmental programs but also by environmental factors, enabling plants to survive under fluctuating conditions. Phytohormones are key signals that link environmental cues to developmental programs; indeed, root hair elongation is known to be controlled by auxin and ethylene. Another phytohormone, cytokinin, also affects root hair growth, while whether cytokinin is actively involved in root hair growth and, if so, how it regulates the signaling pathway governing root hair development have remained unknown. In this study, we show that the two-component system of cytokinin, which involves the B-type response regulators ARABIDOPSIS RESPONSE REGULATOR 1 (ARR1) and ARR12, promotes the elongation process of root hairs. They directly upregulate ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4) encoding a basic helix-loop-helix (bHLH) transcription factor that plays a central role in root hair growth, whereas the ARR1/12-RSL4 pathway does not crosstalk with auxin or ethylene signaling. These results suggest that cytokinin signaling constitutes another input onto the regulatory module governed by RSL4, making it possible to fine-tune root hair growth in changing environments., 13 Mar. 2023, Scientific journal, 10.1093/jxb/erad091 - Refereed, International Journal of Molecular Sciences, MDPI AG, At the Nexus between Cytoskeleton and Vacuole: How Plant Cytoskeletons Govern the Dynamics of Large Vacuoles, Hirotomo Takatsuka; Takumi Higaki; Masaki Ito, Large vacuoles are a predominant cell organelle throughout the plant body. They maximally account for over 90% of cell volume and generate turgor pressure that acts as a driving force of cell growth, which is essential for plant development. The plant vacuole also acts as a reservoir for sequestering waste products and apoptotic enzymes, thereby enabling plants to rapidly respond to fluctuating environments. Vacuoles undergo dynamic transformation through repeated enlargement, fusion, fragmentation, invagination, and constriction, eventually resulting in the typical 3-dimensional complex structure in each cell type. Previous studies have indicated that such dynamic transformations of plant vacuoles are governed by the plant cytoskeletons, which consist of F-actin and microtubules. However, the molecular mechanism of cytoskeleton-mediated vacuolar modifications remains largely unclear. Here we first review the behavior of cytoskeletons and vacuoles during plant development and in response to environmental stresses, and then introduce candidates that potentially play pivotal roles in the vacuole–cytoskeleton nexus. Finally, we discuss factors hampering the advances in this research field and their possible solutions using the currently available cutting-edge technologies., 18 Feb. 2023, 24, 4, 4143, 4143, Scientific journal, 10.3390/ijms24044143
- Refereed, Plant signaling & behavior, MYB3R-SCL28-SMR module with a role in cell size control negatively regulates G2 progression in Arabidopsis., Hirotomo Takatsuka; Yuji Nomoto; Kesuke Yamada; Keito Mineta; Christian Breuer; Takashi Ishida; Ayumi Yamagami; Keiko Sugimoto; Takeshi Nakano; Masaki Ito, Cell size control is one of the prerequisites for plant growth and development. Recently, a GRAS family transcription factor, SCARECROW-LIKE28 (SCL28), was identified as a critical regulator for both mitotic and postmitotic cell-size control. Here, we show that SCL28 is specifically expressed in proliferating cells and exerts its function to delay G2 progression during mitotic cell cycle in Arabidopsis thaliana. Overexpression of SCL28 provokes a significant enlargement of cells in various organs and tissues, such as leaves, flowers and seeds, to different extents depending on the type of cells. The increased cell size is most likely due to a delayed G2 progression and accelerated onset of endoreplication, an atypical cell cycle repeating DNA replication without cytokinesis or mitosis. Unlike DWARF AND LOW-TILLERING, a rice ortholog of SCL28, SCL28 may not have a role in brassinosteroid (BR) signaling because sensitivity against brassinazole, a BR biosynthesis inhibitor, was not dramatically altered in scl28 mutant and SCL28-overexpressing plants. Collectively, our findings strengthen a recently proposed model of cell size control by SCL28 and suggest the presence of diversified evolutionary mechanisms for the regulation and action of SCL28., 28 Dec. 2022, 1, 5, Scientific journal, True, 10.1080/15592324.2022.2153209
- Refereed, Nature Communications, Springer Science and Business Media LLC, A hierarchical transcriptional network activates specific CDK inhibitors that regulate G2 to control cell size and number in Arabidopsis, Yuji Nomoto; Hirotomo Takatsuka; Kesuke Yamada; Toshiya Suzuki; Takamasa Suzuki; Ying Huang; David Latrasse; Jing An; Magdolna Gombos; Christian Breuer; Takashi Ishida; Kenichiro Maeo; Miyu Imamura; Takafumi Yamashino; Keiko Sugimoto; Zoltán Magyar; László Bögre; Cécile Raynaud; Moussa Benhamed; Masaki Ito, Abstract
How cell size and number are determined during organ development remains a fundamental question in cell biology. Here, we identified a GRAS family transcription factor, called SCARECROW-LIKE28 (SCL28), with a critical role in determining cell size in Arabidopsis. SCL28 is part of a transcriptional regulatory network downstream of the central MYB3Rs that regulate G2 to M phase cell cycle transition. We show that SCL28 forms a dimer with the AP2-type transcription factor, AtSMOS1, which defines the specificity for promoter binding and directly activates transcription of a specific set of SIAMESE-RELATED (SMR) family genes, encoding plant-specific inhibitors of cyclin-dependent kinases and thus inhibiting cell cycle progression at G2 and promoting the onset of endoreplication. Through this dose-dependent regulation of SMR transcription, SCL28 quantitatively sets the balance between cell size and number without dramatically changing final organ size. We propose that this hierarchical transcriptional network constitutes a cell cycle regulatory mechanism that allows to adjust cell size and number to attain robust organ growth., Dec. 2022, 13, 1, 1660, 1660, Scientific journal, True, 10.1038/s41467-022-29316-2 - Refereed, Life, MDPI AG, Members of SIAMESE-RELATED Class Inhibitor Proteins of Cyclin-Dependent Kinase Retard G2 Progression and Increase Cell Size in Arabidopsis thaliana, Kesuke J. Yamada; Hirotomo Takatsuka; Junya Hirota; Keto Mineta; Yuji Nomoto; Masaki Ito, Cell size requires strict and flexible control as it significantly impacts plant growth and development. Unveiling the molecular mechanism underlying cell size control would provide fundamental insights into plants’ nature as sessile organisms. Recently, a GRAS family transcription factor SCARECROW-LIKE28 (SCL28) was identified as a determinant of cell size in plants; specifically, SCL28 directly induces a subset of SIAMESE-RELATED (SMR) family genes encoding plant-specific inhibitors of cyclin-dependent kinases (i.e., SMR1, SMR2, SMR6, SMR8, SMR9, SMR13, and SMR14), thereby slowing down G2 phase progression to provide the time to increase cell volume. Of the SMR genes regulated by SCL28, genetic analysis has demonstrated that SMR1, SMR2, and SMR13 cooperatively regulate the cell size downstream of SCL28 in roots and leaves, whereas other SMR members’ contribution remains unexplored. This study shows that in root meristematic cells, SMR9 redundantly participates in cell size control with SMR1, SMR2, and SMR13. Moreover, our cell cycle analysis provides the first experimental evidence that SMR proteins inhibit the G2 progression of proliferating cells. Overall, these findings illuminate the diverse yet overlapping roles of SMR proteins in cell cycle regulation while reinforcing that SMRs are essential downstream effectors of SCL28 to modulate G2 progression and cell size., 31 Aug. 2022, 12, 9, 1356, 1356, Scientific journal, 10.3390/life12091356
- Refereed, Life Science Alliance, Life Science Alliance, LLC, The DREAM complex represses growth in response to DNA damage in Arabidopsis, Lucas Lang; Aladár Pettkó-Szandtner; Hasibe Tunçay Elbaşı; Hirotomo Takatsuka; Yuji Nomoto; Ahmad Zaki; Stefan Dorokhov; Geert De Jaeger; Dominique Eeckhout; Masaki Ito; Zoltán Magyar; László Bögre; Maren Heese; Arp Schnittger, The DNA of all organisms is constantly damaged by physiological processes and environmental conditions. Upon persistent damage, plant growth and cell proliferation are reduced. Based on previous findings that RBR1, the only Arabidopsis homolog of the mammalian tumor suppressor gene retinoblastoma, plays a key role in the DNA damage response in plants, we unravel here the network of RBR1 interactors under DNA stress conditions. This led to the identification of homologs of every DREAM component in Arabidopsis, including previously not recognized homologs of LIN52. Interestingly, we also discovered NAC044, a mediator of DNA damage response in plants and close homolog of the major DNA damage regulator SOG1, to directly interact with RBR1 and the DREAM component LIN37B. Consistently, not only mutants in
NAC044 but also the double mutant of the twoLIN37 homologs and mutants for the DREAM componentE2FB showed reduced sensitivities to DNA-damaging conditions. Our work indicates the existence of multiple DREAM complexes that work in conjunction with NAC044 to mediate growth arrest after DNA damage., Dec. 2021, 4, 12, e202101141, e202101141, Scientific journal, True, 10.26508/lsa.202101141 - Refereed, Chromosome Research, Springer Science and Business Media LLC, Effectiveness of Create ML in microscopy image classifications: a simple and inexpensive deep learning pipeline for non-data scientists, Kiyotaka Nagaki; Tomoyuki Furuta; Naoki Yamaji; Daichi Kuniyoshi; Megumi Ishihara; Yuji Kishima; Minoru Murata; Atsushi Hoshino; Hirotomo Takatsuka, Observing chromosomes is a time-consuming and labor-intensive process, and chromosomes have been analyzed manually for many years. In the last decade, automated acquisition systems for microscopic images have advanced dramatically due to advances in their controlling computer systems, and nowadays, it is possible to automatically acquire sets of tiling-images consisting of large number, more than 1000, of images from large areas of specimens. However, there has been no simple and inexpensive system to efficiently select images containing mitotic cells among these images. In this paper, a classification system of chromosomal images by deep learning artificial intelligence (AI) that can be easily handled by non-data scientists was applied. With this system, models suitable for our own samples could be easily built on a Macintosh computer with Create ML. As examples, models constructed by learning using chromosome images derived from various plant species were able to classify images containing mitotic cells among samples from plant species not used for learning in addition to samples from the species used. The system also worked for cells in tissue sections and tetrads. Since this system is inexpensive and can be easily trained via deep learning using scientists' own samples, it can be used not only for chromosomal image analysis but also for analysis of other biology-related images., 14 Oct. 2021, 29, 3-4, 361, 371, Scientific journal, True, 10.1007/s10577-021-09676-z
- Refereed, International Journal of Molecular Sciences, MDPI AG, Genome Maintenance Mechanisms at the Chromatin Level, Hirotomo Takatsuka; Atsushi Shibata; Masaaki Umeda, Genome integrity is constantly threatened by internal and external stressors, in both animals and plants. As plants are sessile, a variety of environment stressors can damage their DNA. In the nucleus, DNA twines around histone proteins to form the higher-order structure “chromatin”. Unraveling how chromatin transforms on sensing genotoxic stress is, thus, key to understanding plant strategies to cope with fluctuating environments. In recent years, accumulating evidence in plant research has suggested that chromatin plays a crucial role in protecting DNA from genotoxic stress in three ways: (1) changes in chromatin modifications around damaged sites enhance DNA repair by providing a scaffold and/or easy access to DNA repair machinery; (2) DNA damage triggers genome-wide alterations in chromatin modifications, globally modulating gene expression required for DNA damage response, such as stem cell death, cell-cycle arrest, and an early onset of endoreplication; and (3) condensed chromatin functions as a physical barrier against genotoxic stressors to protect DNA. In this review, we highlight the chromatin-level control of genome stability and compare the regulatory systems in plants and animals to find out unique mechanisms maintaining genome integrity under genotoxic stress., 27 Sep. 2021, 22, 19, 10384, 10384, Scientific journal, 10.3390/ijms221910384
- Refereed, Plant biotechnology (Tokyo, Japan), Identification of two tobacco genes encoding MYB3R proteins with repressor function and showing cell cycle-regulated transcript accumulation., Hirotomo Takatsuka; Yuji Nomoto; Satoshi Araki; Yasunori Machida; Masaki Ito, MYB3R family transcription factors play a central role in the regulation of G2/M-specific gene transcription in Arabidopsis thaliana. Among the members of this family, MYB3R3 and MYB3R5 are structurally closely related and are involved in the transcriptional repression of target genes in both proliferating and quiescent cells. This type of MYB3R repressor is widespread in plants; however, apart from the studies on MYB3Rs in Arabidopsis thaliana, little information about them is available. Here we isolated tobacco cDNA clones encoding two closely related MYB3R proteins designated as NtmybC1 and NtmybC2 and determined the nucleotide sequences of the entire coding regions. Phylogenetic analysis suggested that NtmybC1 and NtmybC2 can be grouped into a conserved subfamily of plant MYB3Rs that also contains MYB3R3 and MYB3R5. When transiently expressed in protoplasts prepared from tobacco BY-2 cells, NtmybC1 and NtmybC2 repressed the activity of target promoters and blocked promoter activation mediated by NtmybA2, a MYB3R activator from tobacco. Unlike MYB3R3 and MYB3R5, NtmybC1 and NtmybC2 showed cell cycle-regulated transcript accumulation. In synchronized cultures of BY-2 cells, mRNAs for both NtmybC1 and NtmybC2 were preferentially expressed during the G2 and M phases, coinciding with the expression of NtmybA2 and G2/M-specific target genes. These results not only broadly confirm our fundamental view that this type of MYB3R protein acts as transcriptional repressor of G2/M-specific genes but also suggest a possible divergence of MYB3R repressors in terms of the mechanisms of their action and regulation., 25 Jun. 2021, 38, 2, 269, 275, Scientific journal, False, 10.5511/plantbiotechnology.21.0224a
- Refereed, Journal of Plant Research, Springer Science and Business Media LLC, MYB3R-mediated active repression of cell cycle and growth under salt stress in Arabidopsis thaliana, Toru Okumura; Yuji Nomoto; Kosuke Kobayashi; Takamasa Suzuki; Hirotomo Takatsuka; Masaki Ito, Under environmental stress, plants are believed to actively repress their growth to save resource and alter its allocation to acquire tolerance against the stress. Although a lot of studies have uncovered precise mechanisms for responding to stress and acquiring tolerance, the mechanisms for regulating growth repression under stress are not as well understood. It is especially unclear which particular genes related to cell cycle control are involved in active growth repression. Here, we showed that decreased growth in plants exposed to moderate salt stress is mediated by MYB3R transcription factors that have been known to positively and negatively regulate the transcription of G2/M-specific genes. Our genome-wide gene expression analysis revealed occurrences of general downregulation of G2/M-specific genes in Arabidopsis under salt stress. Importantly, this downregulation is significantly and universally mitigated by the loss of MYB3R repressors by mutations. Accordingly, the growth performance of Arabidopsis plants under salt stress is significantly recovered in mutants lacking MYB3R repressors. This growth recovery involves improved cell proliferation that is possibly due to prolonging and accelerating cell proliferation, which were partly suggested by enlarged root meristem and increased number of cells positive for CYCB1;1-GUS. Our ploidy analysis further suggested that cell cycle progression at the G2 phase was delayed under salt stress, and this delay was recovered by loss of MYB3R repressors. Under salt stress, the changes in expression of MYB3R activators and repressors at both the mRNA and protein levels were not significant. This observation suggests novel mechanisms underlying MYB3R-mediated growth repression under salt stress that are different from the mechanisms operating under other stress conditions such as DNA damage and high temperature., 12 Feb. 2021, 134, 2, 261, 277, Scientific journal, False, 10.1007/s10265-020-01250-8
- Refereed, Methods in Molecular Biology, Springer US, Whole-Mount Immunostaining for the Identification of Histone Modifications in the S-Phase Nuclei of Arabidopsis Roots, Hirotomo Takatsuka; Masaaki Umeda, This chapter describes a method used to analyze the behavior of histone modifications in S phase in Arabidopsis using a whole-mount immunostaining technique. Previous studies have demonstrated that dramatic changes in local chromatin structure are required for the initiation and progression of DNA replication, and that histone modifications play an essential role in the determination of chromatin structure in S phase. Since euchromatic and heterochromatic regions are replicated in distinct S-phase stages, it is important to identify histone modifications at each stage. Here, we introduce a protocol for whole-mount immunostaining combined with 5-ethynyl-2'-deoxyuridine (EdU) staining, which enables the visualization of spatial patterns in histone modifications in the early and late S-phase nuclei of Arabidopsis roots., 2021, 2329, 71, 80, In book, True, 10.1007/978-1-0716-1538-6_6
- Refereed, Journal of Cell Biology, Rockefeller University Press, CDKD-dependent activation of CDKA;1 controls microtubule dynamics and cytokinesis during meiosis, Kostika Sofroni; Hirotomo Takatsuka; Chao Yang; Nico Dissmeyer; Shinichiro Komaki; Yuki Hamamura; Lev Böttger; Masaaki Umeda; Arp Schnittger, Precise control of cytoskeleton dynamics and its tight coordination with chromosomal events are key to cell division. This is exemplified by formation of the spindle and execution of cytokinesis after nuclear division. Here, we reveal that the central cell cycle regulator CYCLIN DEPENDENT KINASE A;1 (CDKA;1), the Arabidopsis homologue of Cdk1 and Cdk2, partially in conjunction with CYCLIN B3;1 (CYCB3;1), is a key regulator of the microtubule cytoskeleton in meiosis. For full CDKA;1 activity, the function of three redundantly acting CDK-activating kinases (CAKs), CDKD;1, CDKD;2, and CDKD;3, is necessary. Progressive loss of these genes in combination with a weak loss-of-function mutant in CDKA;1 allowed a fine-grained dissection of the requirement of cell-cycle kinase activity for meiosis. Notably, a moderate reduction of CDKA;1 activity converts the simultaneous cytokinesis in Arabidopsis, i.e., one cytokinesis separating all four meiotic products concurrently into two successive cytokineses with cell wall formation after the first and second meiotic division, as found in many monocotyledonous species., 03 Aug. 2020, 219, 8, Scientific journal, 10.1083/jcb.201907016
- Plant Physiology, Oxford University Press (OUP), Actin Reorganization Triggers Rapid Cell Elongation in Roots, Hirotomo Takatsuka; Takumi Higaki; Masaaki Umeda, Root growth is controlled by mechanisms underlying cell division and cell elongation, which respond to various internal and external factors. In Arabidopsis (Arabidopsis thaliana), cells produced in the proximal meristem (PM) elongate and differentiate in the transition zone (TZ) and the elongation/differentiation zone (EDZ). Previous studies have demonstrated that endoreplication is involved in root cell elongation; however, the manner by which cells increase in length by more than 2-fold remains unknown. Here, we show that epidermal and cortical cells in Arabidopsis roots undergo two modes of rapid cell elongation: the first rapid cell elongation occurs at the border of the proximal meristem and the TZ, and the second mode occurs during the transition from the TZ to the EDZ. Our previous study showed that cytokinin signaling promotes endoreplication, which triggers the first rapid cell elongation. Our cytological and genetic data revealed that the second rapid cell elongation involves dynamic actin reorganization independent of endoreplication. Cytokinins promote actin bundling and the resultant second rapid cell elongation through activating the signaling pathway involving the cytokinin receptors ARABIDOPSIS HISTIDINE KINASE3 (AHK3) and AHK4 and the B-type transcription factor ARABIDOPSIS RESPONSE REGULATOR2. Our results suggest that cytokinins promote the two modes of rapid cell elongation by controlling distinct cellular events: endoreplication and actin reorganization., Nov. 2018, 178, 3, 1130, 1141, Scientific journal, True, 10.1104/pp.18.00557
- Nature Communications, Arabidopsis R1R2R3-Myb proteins are essential for inhibiting cell division in response to DNA damage, Poyu Chen; Hirotomo Takatsuka; Naoki Takahashi; Rie Kurata; Yoichiro Fukao; Kosuke Kobayashi; Masaki Ito; Masaaki Umeda, Dec. 2017, 8, 1, Scientific journal, 10.1038/s41467-017-00676-4
- Refereed, Frontiers in Plant Science, Epigenetic Control of Cell Division and Cell Differentiation in the Root Apex, Hirotomo Takatsuka; Masaaki Umeda, 24 Dec. 2015, 6, Scientific journal, 10.3389/fpls.2015.01178
- Refereed, The Plant Journal, Cyclin‐dependent kinase‐activating kinases CDKD ;1 and CDKD ;3 are essential for preserving mitotic activity in Arabidopsis thaliana, Hirotomo Takatsuka; Chikage Umeda‐Hara; Masaaki Umeda, Jun. 2015, 82, 6, 1004, 1017, Scientific journal, 10.1111/tpj.12872
- Refereed, Journal of Experimental Botany, Hormonal control of cell division and elongation along differentiation trajectories in roots, Hirotomo Takatsuka; Masaaki Umeda, Jun. 2014, 65, 10, 2633, 2643, Scientific journal, 10.1093/jxb/ert485
- Refereed, Plant and Cell Physiology, VAN4 Encodes a Putative TRS120 That is Required for Normal Cell Growth and Vein Development in Arabidopsis, Satoshi Naramoto; Tomasz Nodzyński; Tomoko Dainobu; Hirotomo Takatsuka; Teruyo Okada; Jiří Friml; Hiroo Fukuda, Apr. 2014, 55, 4, 750, 763, Scientific journal, 10.1093/pcp/pcu012
- Refereed, The Plant Journal, The Arabidopsis cyclin-dependent kinase-activating kinase CDKF;1 is a major regulator of cell proliferation and cell expansion but is dispensable for CDKA activation, Hirotomo Takatsuka; Ryoko Ohno; Masaaki Umeda, Aug. 2009, 59, 3, 475, 487, Scientific journal, 10.1111/j.1365-313x.2009.03884.x
MISC
Presentations
- How does the nucleus move within 'super crowded' plant cells?, 24 Sep. 2025
- 07 Sep. 2023
- The 31st International Conference on Arabidopsis Research, Chromatin-level regulation of endoreplication onset, 25 Jun. 2021
- Hirotomo Takatsuka; Masaaki Umeda, International Plant Molecular Biology, Atrichoblast epidermal cells elongate with polarity in Arabidopsis roots, Aug. 2018, True
- Hirotomo Takatsuka; Masaaki Umeda, Control of Chromatin Structures along Differentiation Trajectories, Mar. 2018, False
- Aug. 2017, False
- Hirotomo Takatsuka; Masaaki Umeda, Plant Organ Growth Symposium, Roles of epigenetic regulation in inducing endoreplication in plants, Mar. 2017, True
- Hirotomo Takatsuka; Masaaki Umeda, 3R Symposium, Role of epigenetic modifications in induction of DNA endoreplication in plants, Nov. 2016, True
- Hirotomo Takatsuka; Masaaki Umeda, International Conference on Arabidopsis Research, Chromatin structure controls the competence of endoreplication, Jun. 2016, True
- Hirotomo Takatsuka; Masaaki Umeda, Keystone Symposia (Plant Epigenetics: From Ge)notype to Phenotype, Roles of epigenetic regulation in inducing DNA polyploidization in plants, Feb. 2016, True
- Sep. 2015, False
- Sep. 2015, False
- Hirotomo Takatsuka; Masaaki Umeda, Epidermal cells elongate with polarity in Arabidopsis roots, Mar. 2015, False
- Hirotomo Takatsuka; Masaaki Umeda, Auxins and Cytokinins in Plant Development, Cytokinins promote rapid cell elongation in Arabidopsis roots, Jun. 2014, True
- Hirotomo Takatsuka; Masaaki Umeda, Actin rearrangement is essential for rapid cell elongation in Arabidopsis roots, Mar. 2014, False
- Masaaki Umeda; Hirotomo Takatsuka; Naoki Takahashi, The essential function of cytokinin in promoting cell elongation in Arabidopsis roots., Mar. 2014, False
- Sep. 2013, False
- Hirotomo Takatsuka; Naoki Takahashi; Masaaki Umeda, SEB Annual Meeting, ytokinins Control Two-step Transition of Root Cells in Arabidopsis, Jul. 2013, True
- Hirotomo Takatsuka; Naoki Takahashi; Masaaki Umeda, Functional Role of Cytokinin Signaling in the Transition Zone of Arabidopsis Roots, Mar. 2013, False
Industrial Property Rights
Research Projects
- 基盤研究(C), 01 Apr. 2025 - 31 Mar. 2028, 25K09686, 植物細胞内で自在なオルガネラ配置を可能にする原理の解明, 高塚 大知, 日本学術振興会, 科学研究費助成事業, 奈良女子大学, 4680000, 3600000, 1080000, kaken
- Oct. 2025 - Sep. 2026, 植物の乾燥・高温耐性を高める新型バイオスティムラント「タカマクロン」の開発・展開, 相馬正護; 高塚大知, 独立行政法人中小機構, FASTAR
- Jul. 2025 - Mar. 2026, 植物の高温耐性を強化する化合物の社会実装を目指した基盤研究, 奈良女子大学プロジェクト経費研究
- Oct. 2022 - Mar. 2026, オルガネラ間の動的相互作用が駆動する細胞分化, 科学技術振興機構, さきがけ
- Grant-in-Aid for Scientific Research (C), Apr. 2022 - Mar. 2025, 22K06293, A study on the vacuole rearrangement during nuclear migration in root hair cells, 高塚 大知, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Kanazawa University, 4290000, 3300000, 990000, kaken
- Nov. 2019 - Mar. 2024, 植物の根の成長原理の解明, 文部科学省, 卓越研究員事業
- Mar. 2022 - Mar. 2023, 双性イオン液体を用いた新しい植物成長調整剤の開発に向けた基盤研究, 北陸銀行, 北陸銀行若手研究助成
- Mar. 2021 - Mar. 2023, Exploring the mechanism that enables plant cells grow actively toward increasing plant biomass, Kanazawa University, 自己超克プログラム
- Apr. 2019 - Mar. 2021, 植物のＤＮＡ倍加誘導において再複製を可能にする仕組みの解明, 高塚 大知, 日本学術振興会, 科学研究費補助金・基盤(C), 0, 0, 0
- Grant-in-Aid for Scientific Research (B), 01 Apr. 2017 - 31 Mar. 2020, 17H03965, Molecular mechanisms of induction of DNA polyploidization, Umeda Masaaki, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Nara Institute of Science and Technology, 17160000, 13200000, 3960000, DNA polyploidization occurs by increasing the DNA content in individual cells. In most plant species, it promotes cell enlargement, thereby increasing organ size. Previous studies suggested that DNA polyploidization is induced by inhibition of cell cycle progression, while we recently revealed that regulation of chromatin structures also participates in the induction process. In this study, we have investigated the key factors associated with chromatin regulation, and found that the plant hormone auxin plays an important role in controlling heterochromatin structures which affect the ability to induce DNA polyploidization., kaken
- Apr. 2017 - Mar. 2019, 植物のDNA倍加誘導におけるエピジェネティック制御メカニズムの解明, 高塚 大知, 日本学術振興会, 科学研究費補助金・若手(B), 0, 0, 0
- Apr. 2017 - Mar. 2018, エピジェネティック改変を利用したDNA倍加誘発による植物バイオマス増産, 高塚 大知, 笹川研究助成, 0, 0, 0
- Apr. 2017 - Mar. 2018, 植物のDNA倍加能力の決定機構の解明, 高塚 大知, 奈良先端科学技術大学院大学財団助成, 0, 0, 0
- Apr. 2017 - Mar. 2018, 植物の活発な細胞成長の基盤となる極性成長の分子メカニズムの解析, 高塚 大知, 稲盛財団研究助成, 0, 0, 0
