Exploration of flowering-promoting substances in bumblebees and elucidation of their mechanisms

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20575
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0601:Agricultural chemistry and related fields
• Research Institution: Keio University
• Principal Investigator: Mori Shinnosuke 慶應義塾大学, 理工学部(矢上), 助教(有期) (10912404)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: マルハナバチ / シロイヌナズナ / 開花促進 / 唾液腺

Outline of Final Research Achievements

The buff-tailed bumblebee (Bombus terrestris) punctures the leaves of unbloomed plants using their mouthparts, which accelerates flowering. In this study, we tested the hypothesis that bees provide flower-promoting substances to leaves. In a flight-cage, the fiery-tailed bumblebee (Bombus ignitus), a species native to Japan, showed no puncturing behavior. However, the extract of B. ignitus had a flower-promoting activity when infiltrated to the leaves of Arabidopsis thaliana. This suggests that chemical factors are responsible for the flowering-promoting phenomenon. When extracts of each body segment (head, thorax, abdomen) were infiltrated to the leaves, the activity was found only in the thorax. Anatomical observations revealed that there was a thoracic salivary gland in the thorax, as exemplified in the western honey bee (Apis mellifera), suggesting that the active substance may be derived from the salivary glands.

Free Research Field

化学生態学

Academic Significance and Societal Importance of the Research Achievements

本研究における試験はハチの体内に植物の開花を促進する化学物質が存在することを示唆した。今後、この開花制御物質を特定できれば、植物生理学的な面からの開花制御メカニズムの研究などにもつながるであろう。また、開花制御の仕組みを理解することで、鑑賞用花卉の安定供給や果実収量の向上など農業上にも多大な貢献が期待できる。