Publications by authors named "Kousuke Hanada"

Heme, an organometallic tetrapyrrole, is widely engaged in oxygen transport, electron delivery, enzymatic reactions, and signal transduction. In plants, it is also involved in photomorphogenesis and photosynthesis. HEME OXYGENASE 1 (HO1) initiates the first committed step in heme catabolism, and it has generally been thought that this reaction takes place in chloroplasts.

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Seasonal changes in spring induce flowering by expressing the florigen, FLOWERING LOCUS T (FT), in . is expressed in unique phloem companion cells with unknown characteristics. The question of which genes are co-expressed with and whether they have roles in flowering remains elusive.

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Natural genetic variation has facilitated the identification of genes underlying complex traits such as stress tolerances. We here evaluated the long-term (L-) heat tolerance (37°C for 5 days) of 174 accessions and short-term (S-) heat tolerance (42°C, 50 min) of 88 accessions and found extensive variation, respectively. Interestingly, L-heat-tolerant accessions are not necessarily S-heat tolerant, suggesting that the tolerance mechanisms are different.

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Duplicated genes show various degrees of functional diversification in plants. We previously identified 1,052 pairs of high diversified duplicates (HDDs) and 600 pairs of low diversified duplicates (LDDs) in Arabidopsis thaliana. Single knock-down of HDDs induced abnormal phenotypic changes because the other gene copy could not compensate for the knock-down effect, while single knock-down of LDDs did not induce abnormal phenotypic changes because of functional compensation by the copy gene.

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Drought is a major abiotic stress that influences rice production. Although the transcriptomic data of rice against drought is widely available, the regulation of small open reading frames (sORFs) in response to drought stress in rice is yet to be investigated. Different levels of drought stress have different regulatory mechanisms in plants.

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Article Synopsis
  • De novo genes from plant mitochondria can be transferred to the nuclear genome, potentially influencing traits like flowering in plants.
  • A specific gene, sORF2146, derived from mitochondrial DNA in Arabidopsis thaliana regulates flowering, with evidence of its emergence through intergenomic gene transfer events.
  • Functional studies show that overexpressing sORF2146 delays flowering, while knocking it down leads to early flowering, indicating its critical role in floral transition.
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Using the whole genome and growth data of Arabidopsis thaliana ecotypes, we identified two genes associated with enhancement of the growth rate in response to elevated CO conditions. Improving plant growth under elevated CO conditions may contribute to enhanced agricultural yield under future global climate change. In this study, we examined the genes implicated in the enhancement of growth rates under elevated CO conditions by analyzing the growth rates of Arabidopsis thaliana ecotypes originating from various latitudes and altitudes throughout the world.

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DNA methylation is an important factor regulating gene expression in organisms. However, whether DNA methylation plays a key role in adaptive evolution is unknown. Here, we show evidence of naturally selected DNA methylation in In comparison with single nucleotide polymorphisms, three types of methylation-methylated CGs (mCGs), mCHGs, and mCHHs-contributed highly to variable gene expression levels among an population.

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Excess soluble iron in acidic soil is an unfavorable environment that can reduce rice production. To better understand the tolerance mechanism and identify genetic loci associated with iron toxicity (FT) tolerance in a highly diverse indica Thai rice population, a genome-wide association study (GWAS) was performed using genotyping by sequencing and six phenotypic data (leaf bronzing score (LBS), chlorophyll content, shoot height, root length, shoot biomass, and root dry weight) under both normal and FT conditions. LBS showed a high negative correlation with the ratio of chlorophyll content and shoot biomass, indicating the FT-tolerant accessions can regulate cellular homeostasis when encountering stress.

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Gene duplication is a major mechanism to create new genes. After gene duplication, some duplicated genes undergo functionalization, whereas others largely maintain redundant functions. Duplicated genes comprise various degrees of functional diversification in plants.

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Increase in atmospheric carbon dioxide (CO) has a significant effect on plant growth and development. To explore the elevated-CO response, we generated transcriptional profiles over a time course (2 h-14 days) of exposure to elevated CO in Arabidopsis thaliana. Genes related to photosynthesis were down-regulated and circadian rhythm-related genes were abnormally regulated in the early to middle phase of elevated CO exposure.

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There is considerable diversity in the specialized metabolites within a single plant species (intra-species) and among different plant species (inter-species). The functional divergence associated with gene duplications largely contributes to the inter-species diversity in the specialized metabolites, whereas the intra-species diversity is due to gene dosage changes gene duplications [i.e.

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In various positive-sense single-stranded RNA viruses, a low-fidelity viral RNA-dependent RNA polymerase (RdRp) confers attenuated phenotypes by increasing the mutation frequency. We report a negative-sense single-stranded RNA virus RdRp mutant strain with a mutator phenotype. Based on structural data of RdRp, rational targeting of key residues, and screening of fidelity variants, we isolated a novel low-fidelity mutator strain of influenza virus that harbors a Tyr82-to-Cys (Y82C) single-amino-acid substitution in the PB1 polymerase subunit.

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The physical interaction of the human growth factor receptor-bound protein 14 (hGrb14) and the insulin receptor (IR) represses insulin signaling. With respect to the recruiting mechanism of hGrb14 to IR respond to insulin stimulus, our previous reports have suggested that phosphorylation of Ser , Ser , and Ser in hGrb14 by glycogen synthase kinase-3 repressed hGrb14-IR complex formation. In this study, we investigated phosphatase-mediated dephosphorylation of the hGrb14 phosphoserine residues.

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Article Synopsis
  • Small signalling peptides, derived from larger proteins, regulate various plant processes, particularly in development and defense against pathogens, but many of those in plant immunity are still undiscovered.
  • We created a research method using transcriptomics and proteomics to identify small secreted proteins (SSPs) in rice that respond to the rice blast fungus and its component, chitin, uncovering 236 SSPs and notably, the immune response peptide (IRP), a potential precursor involved in rice immunity.
  • Our findings indicate that IRP is triggered by bacterial and fungal signals, enhancing defense gene expression and MAPK activation, and highlight our pipeline's effectiveness for discovering SSPs relevant to plant immunity and other functions.
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Recent works have shed light on the long-distance interorgan signaling by which hormone-like peptides precisely regulate physiological effects in a manner similar to phytohormones. Many such peptides have already been identified in the primary model plant, Arabidopsis thaliana. In addition, Arabidopsis genome reanalysis revealed over 7000 novel candidate small coding genes, some of which are likely to be associated with hormone-like peptides.

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Water availability is a key determinant of terrestrial plant productivity. Many climate models predict that water stress will increasingly challenge agricultural yields and exacerbate projected food deficits. To ensure food security and increase agricultural efficiency, crop water productivity must be increased.

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Background: Among human T cell leukemia virus type 1 (HTLV-1)-infected individuals, there is an association between HTLV-1 tax subgroups (subgroup-A or subgroup-B) and the risk of HAM/TSP in the Japanese population. To investigate the role of HTLV-1 subgroups in viral pathogenesis, we studied the functional difference in the subgroup-specific viral transcriptional regulators Tax and HBZ using microarray analysis, reporter gene assays, and evaluation of viral-host protein-protein interaction.

Results: (1) Transcriptional changes in Jurkat Tet-On human T-cells that express each subgroup of Tax or HBZ protein under the control of an inducible promoter revealed different target gene profiles; (2) the number of differentially regulated genes induced by HBZ was 2-3 times higher than that induced by Tax; (3) Tax and HBZ induced the expression of different classes of non-coding RNAs (ncRNAs); (4) the chemokine CXCL10, which has been proposed as a prognostic biomarker for HAM/TSP, was more efficiently induced by subgroup-A Tax (Tax-A) than subgroup-B Tax (Tax-B), in vitro as well as in unmanipulated (ex vivo) PBMCs obtained from HAM/TSP patients; (5) reporter gene assays indicated that although transient Tax expression in an HTLV-1-negative human T-cell line activated the CXCL10 gene promoter through the NF-κB pathway, there was no difference in the ability of each subgroup of Tax to activate the CXCL10 promoter; however, (6) chromatin immunoprecipitation assays showed that the ternary complex containing Tax-A is more efficiently recruited onto the promoter region of CXCL10, which contains two NF-κB binding sites, than that containing Tax-B.

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Peptides encoded by small coding genes play an important role in plant development, acting in a similar manner as phytohormones. Few hormone-like peptides, however, have been shown to play a role in abiotic stress tolerance. In the current study, 17 genes coding for small peptides were found to be up-regulated in response to salinity stress.

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Background: The tertiary gene pool of bread wheat, to which Leymus racemosus belongs, has remained underutilized due to the current limited genomic resources of the species that constitute it. Continuous enrichment of public databases with useful information regarding these species is, therefore, needed to provide insights on their genome structures and aid successful utilization of their genes to develop improved wheat cultivars for effective management of environmental stresses.

Results: We generated de novo DNA and mRNA sequence information of L.

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Article Synopsis
  • Lineage-specific gene duplications play a significant role in the phenotypic differences observed in closely related species, but the exact rates of these duplications and the selective pressures following them remain ambiguous.
  • Using Illumina DNA sequencing of Arabidopsis halleri, researchers established gene groups across Brassicaceae and found that the frequency of gene duplication in the Arabidopsis lineage is about 10 times higher than previously estimated through comparative genomics, likely due to a quick decay of older duplicate genes.
  • Analyses of selection pressures on genes duplicated within the A. halleri-lyrata lineage revealed that duplicated genes experienced more positive selection than non-duplicated genes, and the functional divergence of these duplicates accelerated several million years post-dup
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Alternative promoter usage is a proteome-expanding mechanism that allows multiple pre-mRNAs to be transcribed from a single gene. The impact of this mechanism on the proteome and whether it is positively exploited in normal organismal responses remain unclear. We found that the plant photoreceptor phytochrome induces genome-wide changes in alternative promoter selection in Arabidopsis thaliana.

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Lineage-specific gene duplications contribute to a large variation in specialized metabolites among different plant species. There is also considerable variability in the specialized metabolites within a single plant species. However, it is unclear whether copy number variations (CNVs) derived from gene duplication events contribute to the diversity of specialized metabolites within species.

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Radish ( L. var. ), a widely cultivated root vegetable crop, possesses a large sink organ (the root), implying that photosynthetic activity in radish can be enhanced by altering both the source and sink capacity of the plant.

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