KEIO RESEARCHERS INFORMATION SYSTEM

Academic Degrees 【 Display / hide 】

Academic Degrees 【 Display / hide 】

• life science (Ph.D), The University of Tokyo, Coursework, 2010.03

Books 【 Display / hide 】

Books 【 Display / hide 】

• Natural Rubber: Its Importance and Problems Tackled with Indonesia Through SATREPS Program

  Matsui M., Ota M., Okubo-Kurihara E., Tumewu S.A., Shimizu M., Febbiyanti T.R., Yamamoto Y., Syafaah A., Lestari R., Khaerunnisa S., Makita Y., Kase K., Satria A.E., Sustainable Development Goals Series, 2025

  　View Summary

  Natural rubber, primarily derived from Hevea brasiliensis, is a critical resource for a sustainable society due to its unique properties and indispensable applications in industries such as tire manufacturing, medical supplies, and industrial components. As the global demand for natural rubber continues to rise, ensuring the stability of its supply is increasingly important. However, H. brasiliensis faces significant threats due to its reliance on clonal propagation and diseases such as leaf-fall disease, which jeopardize supply security. To protect natural rubber as a genetic resource, long-term efforts are required to enhance resistance to leaf-fall disease, alongside breeding and conservation initiatives. Additionally, the conservation of rubber trees not only ensures sustainability but also strengthens local economies that depend on rubber cultivation. This chapter discusses the current status of natural rubber supply and H. brasiliensis cultivation, the challenges posed by leaf-fall disease, and our approach to these issues through scientific and integrated methods. By conducting innovative research and taking proactive actions, we aim to secure the long-term sustainability of the natural rubber industry while addressing environmental, economic, and social challenges.

  • Access to Document (DOI)

• Method for Phenotypic Chemical Screening to Identify Cryptochrome Inhibitors

  Okubo-Kurihara E., Ong W.D., Kurihara Y., Kutsuna N., Matsui M., Methods in Molecular Biology, 2021

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  After germination, plants determine their morphogenesis, such as hypocotyl elongation and cotyledon opening, by responding to various wavelengths of light (photomorphogenesis). Cryptochrome is a blue-light photoreceptor that controls de-etiolation, stomatal opening and closing, flowering time, and shade avoidance. Successful incorporation of these phenotypes as indicators into a chemical screening system results in faster selection of candidate compounds. Here, we describe phenotypic screening for the blue-light response of Arabidopsis thaliana seedling and the resulting process that clarifies that the compound obtained in the screening is an inhibitor of cryptochromes.

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Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Comparative genomics and multiomics analyses reveal the evolution and physiological basis of rubber biosynthesis in Hevea species

  Lau N.S., Okubo-Kurihara E., Makita Y., Oktavia F., Kuriyama T., Kurihara Y., Hamasaki H., Nakamura Y., Kadota M., Nishimura O., Kuraku S., Othman A.S., Matsui M.

  Gigascience 14 2025

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  Background: There are multiple species within the Hevea genus, each exhibiting distinct characteristics, but many remain underexplored due to their lower latex productivity. While Hevea brasiliensis is the primary source of natural rubber, other Hevea species represent valuable gene pools that could be leveraged in breeding programs to enhance latex yield, biosynthesis efficiency, and the physicochemical properties of latex. With increasing interest in enhancing natural rubber traits, these lesser-known species are being revisited for their underexplored genetic diversity. Results: In this study, we performed a pangene analysis of 6 Hevea species and varieties, integrating proteomic and lipidomic data to investigate genetic and metabolic variation related to rubber biosynthesis and latex composition. The pangene analysis revealed conserved and expanded ATP-related functions, underscoring ATP’s role in latex production. The proteomic data identified key enzymes involved in rubber biosynthesis and differentially abundant proteins related to latex regeneration, suggesting that regeneration capacity may influence yield efficiency. Lipidomic profiling uncovered species-specific lipid compositions associated with membrane dynamics and rubber particle stability, which may contribute to latex properties. Conclusions: These findings provide valuable insights into Hevea’s genomic and metabolic diversity, supporting future breeding programs aimed at improving natural rubber production and its performance in various applications.

  • Access to Document (DOI)

• Screening of effective pesticides to control rubber tree leaf fall disease (LFD) caused by Neopestalotiopsis and Colletotrichum fungi in Indonesia

  Okubo-Kurihara E., Febbiyanti T.R., Ashari F., Yanagawa Y., Osada E., Kuriyama T., Shimizu M., Diyasti F., Matsui M.

  Journal of Pesticide Science 49 ( 4 ) 277 - 284 2024

  ISSN  1348589X

  　View Summary

  In recent years, the stable supply of natural rubber has been threatened by a new leaf fall disease (LFD) caused by filamentous fungi. We screened pesticides to control the growth of Neopestalotiopsis sp. and Colletotrichum sp., which are considered to be the causal agents of LFD in rubber trees. We identified two effective pesticides, Quinondo 80% WP and Topsin M WP. When these two candidate pesticides were used in combination at 10ppm each, there was enhanced inhibition of growth of both fungal species. Furthermore, the use of Quinondo 80% WP was shown to suppress the development of necrotic lesions caused by Neopestalotiopsis in rubber seedlings. These results suggest that Quinondo 80% WP is effective in controlling the spread of damage caused by LFD infection in rubber trees, and further verification of the concentration and method of application is needed to further demonstrate its effectiveness.

  • Access to Document (DOI)

• Advances in single-cell metabolomics to unravel cellular heterogeneity in plant biology

  Pandian K., Matsui M., Hankemeier T., Ali A., Okubo-Kurihara E.

  Plant Physiology 193 ( 2 ) 949 - 965 2023.10

  ISSN  00320889

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  Single-cell metabolomics is a powerful tool that can reveal cellular heterogeneity and can elucidate the mechanisms of biological phenomena in detail. It is a promising approach in studying plants, especially when cellular heterogeneity has an impact on different biological processes. In addition, metabolomics, which can be regarded as a detailed phenotypic analysis, is expected to answer previously unrequited questions which will lead to expansion of crop production, increased understanding of resistance to diseases, and in other applications as well. In this review, we will introduce the flow of sample acquisition and single-cell techniques to facilitate the adoption of single-cell metabolomics. Furthermore, the applications of single-cell metabolomics will be summarized and reviewed.

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• Identification of a dual orange/far-red and blue light photoreceptor from an oceanic green picoplankton

  Makita Y., Suzuki S., Fushimi K., Shimada S., Suehisa A., Hirata M., Kuriyama T., Kurihara Y., Hamasaki H., Okubo-Kurihara E., Yoshitake K., Watanabe T., Sakuta M., Gojobori T., Sakami T., Narikawa R., Yamaguchi H., Kawachi M., Matsui M.

  Nature Communications 12 ( 1 )  2021.12

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  Photoreceptors are conserved in green algae to land plants and regulate various developmental stages. In the ocean, blue light penetrates deeper than red light, and blue-light sensing is key to adapting to marine environments. Here, a search for blue-light photoreceptors in the marine metagenome uncover a chimeric gene composed of a phytochrome and a cryptochrome (Dualchrome1, DUC1) in a prasinophyte, Pycnococcus provasolii. DUC1 detects light within the orange/far-red and blue spectra, and acts as a dual photoreceptor. Analyses of its genome reveal the possible mechanisms of light adaptation. Genes for the light-harvesting complex (LHC) are duplicated and transcriptionally regulated under monochromatic orange/blue light, suggesting P. provasolii has acquired environmental adaptability to a wide range of light spectra and intensities.

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Reviews, Commentaries, etc. 【 Display / hide 】

Reviews, Commentaries, etc. 【 Display / hide 】

• The blue light signaling inhibitor 3-bromo-7-nitroindazole affects gene translation at the initial reception of blue light in young Arabidopsis seedlings

  Kurihara Y., Akagi C., Makita Y., Kawauchi M., Okubo-Kurihara E., Tsuge T., Aoyama T., Matsui M.

  Plant Biotechnology 41 ( 2 ) 153 - 157 2024

  ISSN  13424580

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  Initial light reception after germination is a dramatic life event when a seedling starts proper morphogenesis. Blue light contains a range of light wavelengths that plants can perceive. A previous report suggested that the chemical compound 3-bromo-7-nitroindazole (3B7N) inhibits blue light-mediated suppression of hypocotyl elongation by physically interacting with the blue light receptor Cryptochrome 1 (CRY1). We previously examined changes of genome-wide gene expression in Arabidopsis seedlings germinated in the dark and then exposed to blue light by RNA-seq and Ribo-seq analyses. The expression of ribosome-related genes was translationally upregulated in response to the initial blue light exposure, depending on signals from both the nucleus and chloroplasts. Here, we re-analyzed our previous data and examined the effect of 3B7N treatment on changes in gene expression upon blue light exposure. The results showed that 3B7N negatively affected translation of ribosome-related genes and, interestingly, the effects were similar to not only those in cry1cry2 mutants but also plants under suppression of photosynthesis. We propose an apparent crosstalk between chloroplast function and blue light signaling.

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• Tracking metabolites at single-cell resolution reveals metabolic dynamics during plant mitosis

  Okubo-Kurihara E., Ali A., Hiramoto M., Kurihara Y., Abouleila Y., Abdelazem E.M., Kawai T., Makita Y., Kawashima M., Esaki T., Shimada H., Mori T., Hirai M.Y., Higaki T., Hasezawa S., Shimizu Y., Masujima T., Matsui M.

  Plant Physiology 189 ( 2 ) 459 - 464 2022.06

  ISSN  00320889

  • Access to Document (DOI)