Biology subjects

Hashimoto, S.

Publications and source records attributed to Hashimoto, S..

At least 19 recordsLinked to original sources

bioRxiv2026

Loss of starch synthase IIa alleviates the negative impact of high temperature on rice starch during grain filling

High temperatures during grain filling stage are becoming increasingly frequent, compromising both grain and eating quality and thereby driving demand for heat-resilient cultivars. Such conditions are known to reduce the expression of granule-bound starch synthase I (GBSSI) and starch branching enzyme IIb (BEIIb), which are involved in starch biosynthesis, resulting in a decrease in amylose content and an increase in long-chain amylopectin. Thus, the present study introduced functional mutation in starch synthase IIa (SSIIa) that increases the proportion of short amylopectin chains to genetically compensate for the high-temperature-induced increase in amylopectin long chain. Rice lines carrying the ss2a mutation were grown at two locations with cooler (Akita) and warmer (Okayama) temperatures. Their grain traits, starch structure, and eating quality were compared. The ss2a mutant lines showed an increased proportion of short amylopectin chains as well as an increased apparent amylose content. Furthermore, these alterations in starch structure varied with the grain-filling temperature of the cultivation sites, ultimately affected eating quality. These results suggest that enriching short amylopectin chain via the ss2a mutation can counteract the increase in long amylopectin chain caused by high temperatures during grain filling, thereby maintaining a desirable starch structure and eating quality.

plant biology↗

bioRxiv2026

Active Nuclear Shuttling Enables Efficient Virus-Free CAR Gene Integration Using Ready-to-Use Lipid Nanoparticles

Non-viral engineering of chimeric antigen receptor T (CAR-T) cells is highly desirable to overcome the cost, safety, and scalability limitations associated with viral vectors and electroporation. However, efficient nuclear delivery and stable genomic integration of DNA in primary human T cells remain major challenges. Here, we established a virus-free CAR-T manufacturing platform using lipid nanoparticles (LNPs) combined with a nuclear localization signal (NLS) shuttle strategy. We developed proprietary ready-to-use LNPs that enable on-demand encapsulation of nucleic acids. To overcome nuclear transport barriers, NLS-fused transposase or genome-editing nuclease was used to bind donor DNA in the cytoplasm and promote active nuclear import. This approach enabled highly efficient and low-toxicity delivery of mRNA and plasmid DNA into primary human T cells. NLS-assisted transposase delivery markedly enhanced genomic integration of the CAR gene, resulting in high expression levels and improved cell viability compared with electroporation-based methods. In addition, TRAC locus-specific targeted integration was achieved more efficiently through end-joining-based repair pathways than through homology-directed repair following LNP delivery. The resulting engineered CAR-T cells exhibited potent and antigen-specific cytotoxic activity. Together, these results demonstrate that NLS-assisted LNP delivery overcomes a key bottleneck in non-viral gene integration and provides a robust strategy for the generation of functional CAR-T cells.

bioengineering↗

bioRxiv2026

RiboPipe: efficient per-transcript codon-resolution ribo-seq coverage imputation for low-coverage transcripts

MotivationRibosome profiling (Ribo-seq) provides codon-resolution measurements of translation; however, many transcripts exhibit sparse or low read coverage, which limits downstream quantitative analyses. Reliable prediction and imputation of codon-resolution coverage for low-coverage transcripts remain computationally challenging. ResultsWe present RiboPipe, an efficient framework for per-transcript codon-resolution Ribo-seq coverage imputation for low-coverage transcripts. RiboPipe is designed around three key principles. First, it jointly optimizes transcript-level mean ribosome load (MRL) prediction and codon-level coverage modeling within a unified objective, enabling consistent learning across both local and transcript-level scales. Second, it introduces a peak-weighted loss that emphasizes high-signal codon positions associated with translational pausing, improving the recovery of functionally relevant coverage peaks. Third, the framework is lightweight and data-efficient, achieving stable performance even when trained on only a small fraction of high-coverage transcripts. Based on two publicly available Ribo-seq datasets (GSE233886 and GSE133393) as instances, we demonstrate stable convergence and consistent prediction accuracy across multiple train-test split ratios. Comparative evaluation of embedding strategies shows that simple one-hot representations achieve superior performance compared with pre-trained language model embeddings under identical training conditions. Overall, RiboPipe provides a computationally efficient and scalable framework for Ribo-seq coverage imputation in low-coverage transcripts. Availability and ImplementationThe source code and associated data can be accessed at https://github.com/yaozhong/riboPipe Contactyaozhong@ims.u-tokyo.ac.jp or imoto@hgc.jp

bioinformatics↗

bioRxiv2026

3D-Manhattan: An interactive visualization tool for multiple GWAS results

Genome-wide association studies (GWAS) are widely used to identify genetic loci underlying various agronomic traits. Conventional Manhattan plots provide an effective two-dimensional (2D) summary of an individual GWAS result. However, recent advances in high-throughput phenotyping have led to study designs that generate multiple GWAS outputs across time points, traits, or experimental conditions. In such settings, biological insight increasingly depends on comparative interpretation of multiple association maps, yet panel-based arrangements of 2D plots fragment related information and impede recognition of shared or dynamic genetic signals. Here, I present 3D-Manhattan, an interactive visualization framework that integrates multiple GWAS results within a unified three-dimensional (3D) coordinate system. By extending the conventional Manhattan plot with an additional axis representing time, trait, or condition, 3D-Manhattan enables simultaneous, axis-aligned comparison of association landscapes while preserving genomic coordinates and statistical values. The tool is implemented as a stand-alone, browser-based application using WebGL-based rendering and supports smooth interaction without server-side computation. The framework provides flexible visualization controls, region highlighting, and variant-level correspondence across datasets, facilitating exploratory analysis of stable and context-dependent genetic associations. Collectively, 3D-Manhattan provides an alternative approach for visualizing multi-dimensional GWAS results and offers a powerful platform for visualizing general a series of genome-wide datasets.

bioinformatics↗

bioRxiv2026

geneSTRUCTURE: A Modern Platform for Visualization of Gene Structures

Even in the era of genomics and pan-genomics, the gene remains the fundamental unit of heredity. Accurate visualization of gene structures provides essential insights into the organization, regulation, and evolution of each gene. Representing elements such as exons, introns, untranslated regions, and functional domains in a clear and interpretable format is particularly important for analyzing complex gene architectures and for communicating results effectively. Despite the availability of several visualization tools, many are limited in their ability to incorporate user-defined annotations or to support interactive and customizable figure generation, which reduces their utility in modern analytical workflows. To address these limitations, we developed geneSTRUCTURE, both command-line-interface and web-based application designed to provide flexible and user-friendly visualization of gene structures based on widely used annotation formats, GFF3 and GTF. In addition to visualizing core gene components, the platform allows users to overlay supplemental annotations, including mutation sites and protein domains, and to adjust layout features in real time. By combining a modern interface with annotation flexibility and high-resolution output, geneSTRUCTURE offers a robust solution for gene-level visualization.

bioinformatics↗

bioRxiv2026

Parallel ZNF598 and GIGYF2 pathways mediate conserved collision-dependent mRNA decay with distinct endonucleolytic features

Quality control of aberrant mRNAs is essential for maintaining cellular homeostasis. Ribosome collisions caused by translational stalling trigger mRNA surveillance pathways that promote degradation of faulty transcripts. In yeast, two major collision-responsive pathways have been proposed: the Hel2-Cue2 pathway and the Syh1-Xrn1 pathway, yet their functional relationship and conservation in mammals have remained unclear. Here, we demonstrate that these two pathways act redundantly to degrade collision-inducing mRNAs in both yeast and mammalian cells. In yeast, we dissect the contribution of Cue2-mediated endonucleolytic cleavage and show that eS7 polyubiquitination-dependent cleavage plays a dominant role in Hel2-Cue2 pathway. In mammals, although the proposed Cue2 homolog N4BP2 is dispensable, we provide the first direct evidence of collision-induced endonucleolytic mRNA cleavage. Together, our findings reveal both conserved and divergent features of ribosome collision-coupled mRNA quality control and expand our understanding of mRNA surveillance and potential therapeutic mRNA implications.

molecular biology↗

bioRxiv2025

Assessing fish diversity in the Amazon: The impact of primers and reference libraries in eDNA surveys

Selecting primers for DNA amplification poses a challenge in environmental DNA (eDNA) studies, particularly in biodiverse tropical ecosystems. Researchers must balance taxonomic coverage, primer specificity, and study feasibility when choosing between a single primer pair and multiple primer pairs. Empirical tests comparing these strategies are essential for improving eDNA protocols, enhancing the detection of aquatic biodiversity, and supporting conservation and environmental monitoring efforts. This study aimed to evaluate how different approaches affect the specificity and efficiency of detecting fish species in eDNA samples from the Teles Pires River basin. We (1) synthesized modified versions of primers commonly used in ichthyofaunal surveys; (2) compared the results generated by these modified primers with the standard primer versions; and (3) evaluated the species detection using two reference sequence databases: a global taxonomic database (GenBank) and a locally constructed taxonomic database containing samples of fish species previously collected in situ. The 12S-V5_mod primers detected the most fish species across the databases (67, 104, and 130 in the Midori2, Local, and joint databases, respectively), followed by the MiFish_mod primers, which detected 47, 101, and 114 species. Finally, the MiFish primers detected 39, 73, and 78 species. The 12S-V5_mod primers also had lower taxonomic specificity of fish species and amplified a broader range of vertebrate taxa than the MiFish_mod primers. The modified primers outperformed the MiFish primers, and detectability nearly doubled when the Local reference database was used. These results speak to the critical need for constructing reference databases of regional biodiversity, and the need to incorporate multiple primer pairs in eDNA studies.

genetics↗

bioRxiv2025

Modulation of prefrontal functional connectivity by anodal tDCS over left DLPFC predicts performance enhancement in competitive swimmers: A simultaneous tDCS-fNIRS, double-blind, sham-controlled crossover study

While transcranial direct current stimulation (tDCS) has been proposed as a method to enhance physical performance in athletes, the underlying neural mechanisms and the reasons for the widely reported individual variability in its effects remain unclear. This study investigated whether prefrontal hemodynamic responses, measured by functional near-infrared spectroscopy (fNIRS), are associated with the effects of anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC) on swimming performance. In a double-blind, sham-controlled, crossover design, eight trained male swimmers performed 100 m freestyle trials under both anodal tDCS and sham conditions. We recorded prefrontal cortical activation and functional connectivity using fNIRS during a resting-state period and a subsequent stimulation period. While tDCS led to a numerical improvement in 100 m freestyle time, the overall effect was not statistically significant. The fNIRS analyses revealed that tDCS significantly reduced intra-hemispheric functional connectivity, especially in the stimulated left prefrontal cortex. Crucially, the magnitude of this connectivity reduction correlated with the degree of performance improvement, suggesting a direct brain-behavior link. Exploratory analyses further suggested that baseline functional connectivity could predict an individuals neural response to tDCS, with those having higher baseline connectivity showing a greater reduction. These findings suggest that tDCS over the left DLPFC may enhance physical performance by increasing the neural efficiency of prefrontal networks. Therefore, baseline functional connectivity is a promising physiological biomarker that could be used to personalize neuromodulation protocols in athletes.

neuroscience↗

bioRxiv2025

Senotherapeutic potential against xeroderma pigmentosum

Xeroderma pigmentosum (XP) is an inherited photoaging syndrome caused by mutations in genes involved in the nucleotide excision repair (NER) pathway. XP patients exhibit hypersensitivity to ultraviolet (UV) radiation, leading to accelerated skin aging and requiring lifelong sun avoidance. Here, we demonstrate that UV-induced DNA damage triggers cellular senescence and up-regulates senescence-associated secretory phenotype (SASP) genes in melanocytes derived from an XP patient. To explore the potential therapeutics for XP, we developed a cisplatin-based drug screening system and identified JAK inhibitors and curcuminoids as promising senomorphic agents. In addition, two classes of senolytic agents, BCL-2-like protein inhibitors and HSP90 inhibitors, effectively eliminate senescent melanocytes. Further analysis demonstrates that senomorphic treatment effectively counteracts senescence and reduces SASP gene expression in XP-derived melanocytes. Moreover, genes in senescence-related pathways, including the JAK/STAT, Type I interferon (IFN-I), and PI3K/AKT pathways, which are activated by both UV irradiation and cisplatin treatment, are down-regulated by senomorphic treatment. This study highlights a potential senotherapeutic strategy for XP, which may help alleviate photoaging symptoms in XP patients.

cell biology↗

bioRxiv2025

Hypomorphic Lig4 gene mutation in mice predisposes to Th1-skewing intestinal inflammation

Dysregulation of DNA double-strand break (DSB) repair leads to adaptive immunodeficiency, whereas the remaining lymphocytes are aberrantly activated and provoke inflammations. However, no model mice were available to consistently manifest inflammation under defective DSB repair. We generated mutant mice carrying a missense mutation p.W447C in the gene encoding DNA ligase IV (LIG4), critical for DSB repair. Lig4W447C/W447C mice showed growth retardation and severe intestinal inflammations under adaptive immunodeficiency. The inflammations were featured by marked infiltration of T helper type 1 (Th1) cells and macrophages and was dependent on lymphocytes. When Ifng was deleted, Th2 and Th17 instead of Th1 cells drove the inflammations. Lig4W447C/W447C mice showed expansion of oligoclonal T cells with T cell receptor repertoire skewed towards more proximal 3 V and 5 J gene segments. Thus, our novel hypomorphic Lig4 mutant mice show that defective DSB repair leads to Th1-dependent intestinal inflammations under severe adaptive immunodeficiency.

immunology↗

bioRxiv2025

Immunological characterization of peritoneal exudate cells in liver cirrhosis patients

BACKGROUND AND AIMSLiver cirrhosis (LC) is the end stage of liver fibrosis caused by various chronic liver diseases. Patients with LC often develop ascites containing peritoneal exudate cells (PECs). However, those cells have not been fully immunologically characterized. In this study, we clarify immune cell profiles of PECs from patients with LC. APPROACH AND RESULTSPECs were collected from patients with LC or patients receiving continuous ambulatory peritoneal dialysis (CAPD) as a non-cirrhotic control and subjected to single-cell RNA sequencing (scRNA-seq), bulk RNA sequencing (RNA-seq) and flowcytometry analyses. Analysis of scRNA-seq revealed that dendritic cells (DCs) and macrophages were major populations in CAPD patient-derived PECs, while those cells were decreased and T cells were most abundant in LC patient-derived PECs. Notably, FCGR3A-expressing macrophages were dominant over DCs and GATA6-expressing macrophages in LC patient-derived PECs. Bulk RNA-seq analysis further clarified expression of a set of genes was up- or down-regulated along with LC severity. Especially, expression of T cell signature genes was featured by its increase at Child-Pugh class B, but decrease at Child-Pugh class C. Flowcytometry analysis showed increase of T cells, decrease of DCs and macrophages, and increased expression of CD16 and CD163 in CD1cintCD14high cells corresponding to FCGR3A-expressing macrophages in LC patient-derived PECs. CONCLUSIONSIn LC patient-derived PECs, myeloid and T cell populations and their gene expression profiles were fluctuated with severity. Our findings should contribute to further development of diagnosis or therapeutic maneuver for LC.

immunology↗

bioRxiv2025

Involvement of orexin nerves in early stage of Alzheimer's disease model mice and preventive effect of orexin receptor antagonists

BackgroundMild cognitive impairment (MCI) is a condition between healthy cognition and dementia with a high probability of progression to Alzheimers disease (AD). Elevated levels of orexin (OX) have been reported in the cerebrospinal fluid of patients with MCI and AD. ObjectiveTo investigate the efficacy of dual OX receptor antagonists (suvorexant and lemborexant) in an early-stage AD mouse model (App-KI). MethodsThe expression of the OX receptor gene, the levels of suvorexant and lemborexant in the brain after a single oral dose, and their effects on locomotor activity were investigated in wild-type mice. In addition, the cognitive function of wild-type and App-KI mice was assessed using the Y-maze test after oral administration of suvorexant or lemborexant once a day for 60 d. After the behavioral test, amyloid-beta levels were quantified in the hippocampal CA1 region of App-KI mice. ResultsThe expression of the OX receptor gene was highest in the lateral hypothalamus and was also observed in other brain regions. Drug levels peaked at 20-40 min for suvorexant and 15 min for lemborexant and declined, still detectable 24 h later. Locomotor activity was reduced after suvorexant or lemborexant administration; however, 24 h after administration, locomotor activity did not differ from the control group. In particular, the Y-maze test showed that suvorexant and lemborexant prevented cognitive impairment in App-KI mice. Furthermore, suvorexant and lemborexant suppressed amyloid-beta accumulation in the hippocampal CA1 region of App-KI mice. ConclusionThe results suggest that suvorexant and lemborexant effectively suppress the early stages of AD.

animal behavior and cognition↗

bioRxiv2024

STRESS GRANULE-RELATED GENES DURING EMBRYOGENESIS OF AN INVERTEBRATE CHORDATE

Control of global protein synthesis through the assembly of stress granules (SGs) represents a strategy adopted by eukaryotic cells to face various stress conditions. TIAR, TTP and G3BP are key components of SGs, allowing the regulation of mRNA stability and thus controlling not only stress responses but also cell proliferation and differentiation. In the present work we aimed to investigate the role of tiar, ttp and g3bp during embryogenesis of the solitary ascidian Ciona robusta, both in physiological and stress conditions. We carried out CRISPR/Cas9 knockout to evaluate the effects on normal embryonic development, and gene reporter assays to study time and tissue specificity of gene expression, together with whole mount ISH and qRT-PCR. To induce acute stress conditions, we used iron and cadmium as "essential" and "non-essential" metals, respectively. Our results highlight, for the first time, the importance of tiar, ttp and g3bp in the control of development of mesendodermal tissue derivatives during embryogenesis of an invertebrate chordate. HIGHLIGHTS- Mesenchyme, nervous cells, and endoderm are the embryonic regions mainly transcribing cr-tiarx1, cr-ttp and cr-g3bp2 during metal stress conditions. - Only cr-ttp transcription is regulated at mid gastrula stage. - The highest transcription levels are reached in hatching larvae after iron exposure. - cr-tiarx1, cr-ttp and cr-g3bp2 knockouts resulted in impaired embryogenesis.

developmental biology↗

bioRxiv2023

Chemo-senolytic therapeutic potential against angiosarcoma

Angiosarcoma is an aggressive soft-tissue sarcoma with a poor prognosis. Chemotherapy for this cancer typically employs paclitaxel, one of the taxanes (genotoxic drugs), although it has a limited effect due to chemoresistance for prolonged treatment. Here we examine a new angiosarcoma treatment approach that combines chemotherapeutic and senolytic agents. We first find that the chemotherapeutic drugs, cisplatin and paclitaxel, efficiently induce cellular senescence of angiosarcoma cells. Subsequent treatment with a senolytic agent, ABT-263, eliminates senescent cells through the activation of the apoptotic pathway. In addition, expression analysis indicates that senescence-associated secretory phenotype (SASP) genes are activated in senescent angiosarcoma cells and that ABT-263 treatment eliminates senescent cells expressing genes in the type-I interferon (IFN-I) pathway. Moreover, we show that cisplatin treatment alone requires a high dose to remove angiosarcoma cells, whereas a lower dose of cisplatin is sufficient to induce senescence, followed by the elimination of senescent cells by senolytic treatment. This study sheds light on a potential therapeutic strategy against angiosarcoma by combining a relatively low dose of cisplatin with the ABT-263 senolytic agent, which can help ease the deleterious side effects of chemotherapy.

cancer biology↗

bioRxiv2023

Uncovering the links between physical activity and prosocial behaviour: A functional near-infrared spectroscopy hyperscanning study on brain connectivity and synchrony

The prevalence of sedentary lifestyles in modern society raises concerns about their potential association with poor brain health, particularly in the lateral prefrontal cortex (LPFC), which is crucial for human prosocial behaviour. Here, we show the relationship between physical activity and prosocial behaviour, focusing on potential neural markers, including intra-brain functional connectivity and inter-brain synchrony in the LPFC. Forty participants, each paired with a stranger, underwent evaluation of neural activity in the LPFC using functional near-infrared spectroscopy hyperscanning during eye-to-eye contact and an economic game. Results showed that individuals with exercise habits and more leisure-time physical activity demonstrated greater reciprocity, less trust, longer decision-making time, and stronger intra-brain connectivity in the dorsal LPFC and inter-brain synchrony in the ventral LPFC. Our findings suggest that a sedentary lifestyle may alter human prosocial behaviour by impairing adaptable prosocial decision-making in response to social factors through altered intra-brain functional connectivity and inter-brain synchrony.

neuroscience↗

bioRxiv2021

Neprilysin-sensitive amyloidogenic Aβ versus IDE-sensitive soluble Aβ: a probable mechanistic cause for sporadic Alzheimer's disease

Neprilysin (NEP) and insulin-degrading enzyme (IDE) are considered the two major catabolic enzymes that degrade amyloid {beta} peptide (A{beta}), the primary cause of Alzheimers disease (AD). However, their roles in A{beta} metabolism in vivo have never been compared in an impartial and side-by-side manner. Here, we crossbred single App knock-in mice with NEP (Mme) KO mice and with IDE (Ide) KO mice to generate double mutants that were analyzed for their biochemical and A{beta} pathology properties. We found that NEP is responsible for the metabolism of amyloidogenic insoluble A{beta} whereas IDE affects soluble A{beta}. A deficiency of NEP, but not of IDE, augmented the formation of A{beta} plaques, dystrophic neurites, and astrocytic and microglial activation, all of which are key pathological events in the development of AD. In addition, a deficiency of NEP had no significant impact on the levels of various neuropeptides (somatostatin, substance P, cholecystokinin, and neuropeptide Y), well known to be in vitro substrates for NEP, presumably because NEP is expressed in secretory vesicles and on the presynaptic membranes of excitatory neurons while most if not all neuropeptides are secreted from inhibitory neurons. This argues against the concern that NEP up-regulation for treatment of preclinical AD would reduce the levels of these neuropeptides. These findings indicate that NEP relatively selectively degrades A{beta} in the brain. Whereas familial AD (FAD) is unambiguously caused by an increased anabolism of A{beta}, and of A{beta} 42 and A{beta} 43 in particular, the anabolism of A{beta} appears unaffected before its deposition in the brain that subsequently leads to the onset of sporadic AD (SAD). These observations thus suggest that NEP-sensitive amyloidogenic A{beta} likely plays a primary pathogenic role in the etiology of SAD. Our findings are consistent with the aging-dependent decline of NEP expression in human brain and with recent genome-wide association studies (GWAS) indicating that variants of the gene encoding NEP (MME) are associated with the risk of SAD development. Taken together, our results imply that the aging-associated decrease in NEP expression is a primary cause of SAD and could thus be a target for the treatment of preclinical AD once other factors such as apolipoprotein E genotypes have also been considered.

neuroscience↗

bioRxiv2021

TAS-Seq: a robust and sensitive amplification method for beads-based scRNA-seq

Single-cell RNA-sequencing (scRNA-seq) is valuable for analyzing cellular heterogeneity. Cell composition accuracy is critical for analyzing cell-cell interaction networks from scRNA-seq data. We developed terminator-assisted solid-phase cDNA amplification and sequencing (TAS-Seq) for scRNA-seq based on a terminator, terminal transferase, and nanowell/bead-based scRNA-seq platform; TAS-Seq showed high tolerance to variations in the terminal transferase reaction, which complicate the handling of existing terminal transferase-based scRNA-seq methods. In murine and human lung samples, TAS-Seq yielded scRNA-seq data that were highly correlated with flow-cytometric data, showing higher gene-detection sensitivity and more robust detection of important cell-cell interactions and expression of growth factors/interleukins in cell subsets than 10X Chromium v2 and Smart-seq2. Expanding TAS-Seq application will improve understanding and atlas construction of lung biology at the single-cell level.

genomics↗

bioRxiv2021

Verification of our empirical understanding of the physiology and ecology of two contrasting plantation species using a trait database

The effects of climate change on forest ecosystems take on increasing importance more than ever. Information on plant traits is a powerful predictor of ecosystem dynamics and functioning. We reviewed the major ecological traits, such as foliar gas exchange and nutrients, xylem morphology and drought tolerance, of Cryptomeria japonica and Chamaecyparis obtusa, which are major timber species in East Asia, especially in Japan, by using a recently developed functional trait database for both species (SugiHinokiDB). Empirically, C. obtusa has been planted under drier conditions, whereas C. japonica has been planted under wetter conditions. Our analyses revealed followings: The maximum photosynthetic rate, stomatal conductance, foliar nutrient content and soil-to-foliage hydraulic conductance were higher in C. japonica than in C. obtusa and were consistent with the higher growth rate of C. japonica. In contrast, the foliar turgor loss point and xylem pressure corresponding to 50% conductivity, which indicate drought tolerance, were lower in C. obtusa than in C. japonica and are consistent with the drier habitat of C. obtusa. Ontogenetic shifts were also observed; as the age and height of the trees increased, many foliar nutrient concentrations decreased, and the foliar minimum midday water potential and specific leaf area also decreased. This suggests that an ontogenetic reduction in photosynthesis occurred due to an increase in drought stress with tree height and age. However, among the Cupressaceae worldwide, the drought tolerance of C. japonica and C. obtusa is not as high. This may be related to the fact that the Japanese archipelago has historically not been subjected to strong dryness. The maximum photosynthetic rate showed intermediate values within the family, indicating that C. japonica and C. obtusa exhibit relatively high growth rates in the Cupressaceae family, and this is thought to be the reason why they have been selected as economically suitable timber species in Japanese forestry. This study clearly demonstrated that the plant trait database provides us a promising opportunity to verify out empirical knowledge of plantation management and helps us to understand effect of climate change on plantation forests by using trait-based modelling.

ecology↗