Maeda, Taro



Graduate School of Media and Governance (Shonan Fujisawa)


Project Assistant Professor (Non-tenured)/Project Research Associate (Non-tenured)/Project Instructor (Non-tenured)

Career 【 Display / hide

  • 2013

    National Institute for Basic Biology, 研究員

  • 2020.04

    Ryukoku University, 情報生物学研究室, 研究員

  • 2021.11

    Keio University, Graduate School of Media and Governance, Project research associate


Research Areas 【 Display / hide

  • Life Science / Evolutionary biology


Papers 【 Display / hide

  • Asymbiotic mass production of the arbuscular mycorrhizal fungus Rhizophagus clarus

    Tanaka S., Hashimoto K., Kobayashi Y., Yano K., Maeda T., Kameoka H., Ezawa T., Saito K., Akiyama K., Kawaguchi M.

    Communications Biology (Communications Biology)  5 ( 1 )  2022.12

    ISSN  2399-3642

     View Summary

    Arbuscular mycorrhizal (AM) symbiosis is a mutually beneficial interaction between fungi and land plants and promotes global phosphate cycling in terrestrial ecosystems. AM fungi are recognised as obligate symbionts that require root colonisation to complete a life cycle involving the production of propagules, asexual spores. Recently, it has been shown that Rhizophagus irregularis can produce infection-competent secondary spores asymbiotically by adding a fatty acid, palmitoleic acid. Furthermore, asymbiotic growth can be supported using myristate as a carbon and energy source for their asymbiotic growth to increase fungal biomass. However, the spore production and the ability of these spores to colonise host roots were still limited compared to the co-culture of the fungus with plant roots. Here we show that a combination of two plant hormones, strigolactone and jasmonate, induces the production of a large number of infection-competent spores in asymbiotic cultures of Rhizophagus clarus HR1 in the presence of myristate and organic nitrogen. Inoculation of asymbiotically-generated spores promoted the growth of host plants, as observed for spores produced by symbiotic culture system. Our findings provide a foundation for the elucidation of hormonal control of the fungal life cycle and the development of inoculum production schemes.

  • Clonal spore populations in sporocarps of arbuscular mycorrhizal fungi

    Masahide Yamato and Hiroki Yamada and Taro Maeda and Kohei Yamamoto and Ryota Kusakabe and Takamichi Orihara

    Mycorrhiza (Springer Science and Business Media {LLC})   2022.06

  • Chloroplast acquisition without the gene transfer in kleptoplastic sea slugs, Plakobranchus ocellatus

    Maeda T., Takahashi S., Yoshida T., Shimamura S., Takaki Y., Nagai Y., Toyoda A., Suzuki Y., Arimoto A., Ishii H., Satoh N., Nishiyama T., Hasebe M., Maruyama T., Minagawa J., Obokata J., Shigenobu S.

    eLife (eLife)  10 2021.04

     View Summary

    Some sea slugs sequester chloroplasts from algal food in their intestinal cells and photosynthesize for months. This phenomenon, kleptoplasty, poses a question of how the chloroplast retains its activity without the algal nucleus. There have been debates on the horizontal transfer of algal genes to the animal nucleus. To settle the arguments, this study reported the genome of a kleptoplastic sea slug, Plakobranchus ocellatus, and found no evidence of photosynthetic genes encoded on the nucleus. Nevertheless, it was confirmed that light illumination prolongs the life of mollusk under starvation. These data presented a paradigm that a complex adaptive trait, as typified by photosynthesis, can be transferred between eukaryotic kingdoms by a unique organelle transmission without nuclear gene transfer. Our phylogenomic analysis showed that genes for proteolysis and immunity undergo gene expansion and are up-regulated in chloroplast-enriched tissue, suggesting that these molluskan genes are involved in the phenotype acquisition without horizontal gene transfer.

  • Mechanisms of rice endophytic bradyrhizobial cell differentiation and its role in nitrogen fixation

    Greetatorn T., Hashimoto S., Maeda T., Fukudome M., Piromyou P., Teamtisong K., Tittabutr P., Boonkerd N., Kawaguchi M., Uchiumi T., Teaumroong N.

    Microbes and Environments (Microbes and Environments)  35 ( 3 ) 1 - 14 2020

    ISSN  13426311

     View Summary

    Bradyrhizobium sp. strain SUTN9-2 is a symbiotic and endophytic diazotrophic bacterium found in legume and rice plants and has the potential to promote growth. The present results revealed that SUTN9-2 underwent cell enlargement, increased its DNA content, and efficiently performed nitrogen fixation in response to rice extract. Some factors in rice extract induced the expression of cell cycle and nitrogen fixation genes. According to differentially expressed genes (DEGs) from the transcriptomic analysis, SUTN9-2 was affected by rice extract and the deletion of the bclA gene. The up-regulated DEGs encoding a class of oxidoreductases, which act with oxygen atoms and may have a role in controlling oxygen at an appropriate level for nitrogenase activity, followed by GroESL chaperonins are required for the function of nitrogenase. These results indicate that following its exposure to rice extract, nitrogen fixation by SUTN9-2 is induced by the collective effects of GroESL and oxidoreductases. The expression of the sensitivity to antimicrobial peptides transporter (sapDF) was also up-regulated, resulting in cell differentiation, even when bclA (sapDF) was mutated. This result implies similarities in the production of defensin-like antimicrobial peptides (DEFs) by rice and nodule-specific cysteine-rich (NCR) peptides in legume plants, which affect bacterial cell differentiation.

  • Structure-Specific Regulation of Nutrient Transport and Metabolism in Arbuscular Mycorrhizal Fungi

    Hiromu Kameoka, Taro Maeda, Nao Okuma, Masayoshi Kawaguchi

    Plant and Cell Physiology (Oxford University Press (OUP))  60 ( 10 ) 2272 - 2281 2019.10

    Accepted,  ISSN  00320781

     View Summary


    Arbuscular mycorrhizal fungi (AMF) establish symbiotic relationships with most land plants, mainly for the purpose of nutrient exchange. Many studies have revealed the regulation of processes in AMF, such as nutrient absorption from soil, metabolism and exchange with host plants, and the genes involved. However, the spatial regulation of the genes within the structures comprising each developmental stage is not well understood. Here, we demonstrate the structure-specific transcriptome of the model AMF species, Rhizophagus irregularis. We performed an ultra-low input RNA-seq analysis, SMART-seq2, comparing five extraradical structures, germ tubes, runner hyphae, branched absorbing structures (BAS), immature spores and mature spores. In addition, we reanalyzed the recently reported RNA-seq data comparing intraradical mycelium and arbuscule. Our analyses captured the distinct features of each structure and revealed the structure-specific expression patterns of genes related to nutrient transport and metabolism. Of note, the transcriptional profiles suggest distinct functions of BAS in nutrient absorption. These findings provide a comprehensive dataset to advance our understanding of the transcriptional dynamics of fungal nutrition in this symbiotic system.

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Reviews, Commentaries, etc. 【 Display / hide

  • ヒメナガカメムシ菌細胞内共生細菌のゲノム解析

    松浦優, 竹下和貴, 前田太郎, 三浦徹, 重信秀治, 菊池義智, 深津武馬

    日本応用動物昆虫学会大会講演要旨 59th   111 2015.03

  • 序論 共生研究における新しいゲノム科学的手法 (特集 共生ゲノム学 : 生物共進化のプリンシプルに迫る)

    前田 太郎, 重信 秀治

    遺伝 : 生物の科学 (エヌ・ティー・エス)  67 ( 4 ) 435 - 440 2013.07

    ISSN  0387-0022

  • PK-024 ホソヘリカメムシ共生細菌Burkholderia sp. RPE64株の比較ゲノム解析(共生・相互作用,ポスター発表)

    竹下 和貴, 二河 成男, 柴田 朋子, 前田 太郎, 西山 智明, 重信 秀治, 長谷部 光泰, 深津 武馬, 菊池 義智

    日本微生物生態学会講演要旨集 (日本微生物生態学会)   ( 29 ) 141 - 141 2013

  • 藻類からウミウシへ光合成遺伝子が移動?

    前田 太郎

    藻類 = The bulletin of Japanese Society of Phycology (日本藻類学会)  57 ( 1 ) 10 - 12 2009.03

    ISSN  0038-1578

Research Projects of Competitive Funds, etc. 【 Display / hide

  • 盗葉緑体現象における遺伝子伝搬に依らない形質伝搬機構をタンパク質解析から解明する


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 基盤研究(C), Principal investigator