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Poster

Session: Session 1 Presenting Authors at Posters (Evens)

P-140 - A transcription factor Pro1 frequently induces morphological changes in mycelia and loss of female fertility during long-term culture in the rice blast fungus.

Tuesday, July 15, 2025
09:55 - 11:30  
Location: Confex Hall 3
Microbial infection strategies (pathogens & non-pathogens)

    Presenting Author(s)

  • RK

    Rei Kida

    Graduate school of Science and Technology, Tokyo University of Science, Japan
    Noda, Chiba, Japan

    • Author(s)

  • KK

    Kohtetsu Kita

    Graduate school of Science and Technology, Tokyo University of Science, Japan
    Noda, Chiba, Japan

  • MU

    Momotaka Uchida

    Medical Mycology Research Center, Chiba University, Japan
    Chiba, Chiba, Japan

  • LA

    Lassagne Alexandre

    CIRAD, UMR PHIM, F-34398 Montpellier, France; PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
    Montpellier, Languedoc-Roussillon, France

  • DT

    Didier Tharreau

    CIRAD, UMR PHIM, F-34398 Montpellier, France; PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
    Montpellier, Languedoc-Roussillon, France

  • EF

    Elisabeth Fournier

    PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
    Montpellier, Languedoc-Roussillon, France

  • TA

    Tsutomu Arie

    Professor
    United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Japan
    fuchu, Tokyo, Japan

  • TK

    Takashi Kamakura

    Graduate school of Science and Technology, Tokyo University of Science, Japan
    Noda, Chiba, Japan

  • TA

    Takayuki Arazoe

    Graduate school of Science and Technology, Tokyo University of Science, Japan
    Noda, Chiba, Japan

The rice blast fungus Pyricularia oryzae (Magnaporthe oryzae) is a heterothallic ascomycete that causes destructive disease in cultivated rice. The infection cycle of this fungus consists of asexual reproduction, and most field isolates lost female fertility. Several isolates collected in one population from the area of the origin of this pathogen (South East Asia) retained female fertility, suggesting that female fertility has been lost during spread of the pathogen in various ecosystems all around the world. We previously showed that functional mutations in Pro1, a global transcriptional regulator, cause the loss of female fertility in nature. In this study, we found that partial morphological changes, velvet-like mycelia, of female-fertile isolates occurred during long-term culture (2–4 weeks) on agar media. We also showed that isolated lines from the modified mycelia lost female fertility due to mutations in the velvet family gene VeA. To investigate whether Pro1 is involved in mycelial morphology, female-sterile isolates with dysfunctional Pro1 were complemented by functional Pro1. The transformants showed mycelial morphology similar to that of female-fertile isolates, and modified mycelia appeared during long-term culture. In addition, Pro1-deletion mutants of female-fertile isolates showed velvet-like mycelia. These results suggest that Pro1 regulates both female fertility and mycelial morphology but may trigger appearance of modified mycelia during long-term culture.