Understanding survival strategy of C1-microorgansms in the phyllosphere from in vitro and in natura experiments

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02870
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 38020:Applied microbiology-related
• Research Institution: Kyoto University
• Principal Investigator: SAKAI Yasuyoshi 京都大学, 農学研究科, 教授 (60202082)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: C1微生物 / C1酵母 / C1細菌 / メタノール誘導 / 脱抑制 / ペルオキシソーム / ペキソファジー

Outline of Final Research Achievements

Methylotrophic yeasts and bacteria, that can utilize methanol as the sole source of carbon and energy, colonize the plant leaf surface (phyllosphere). The aim of this study was to elucidate the mechanism for survival strategy of C1-microorganisms in the phyllosphere. We set up experimental conditions not only in vitro but also in natura, and investigated molecular mechanisms for methanol-induced gene expression and regulation of pexophagy in the methylotrophic yeast. As a result, we elucidated the regulatory mechanism of peroxisome biogenesis and degradation in response to methanol concentration. On the other hand, we successfully tracked dominant colonization of methylotrophic bacteria in the phyllosphere by using the fluorescent microscopy and flowcytometry. Genetic and biochemical properties of the clock gene homolog KaiC upon temperature or light change were also investigated.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

C1酵母では、メタノール誘導制御機構やペキソファジー制御機構の解析から、メタノール濃度が日周変動する葉面環境での生存戦略として、メタノール濃度に応答したペルオキシソーム合成と分解の制御機構を明らかにした。C1細菌では、蛍光顕微鏡やフローサイトメトリーを用いて優占化過程を追跡することに成功するとともに、培養温度シフトや光応答時における時計遺伝子ホモログKaiCの生理機能に関する遺伝学的および生化学的特性を明らかにした。