Chemical defense of conifers using the natural environment unraveling from the oxidation of essential oils

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05718
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40020:Wood science-related
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Kusumoto Norihisa 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (80537168)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: トドマツ樹皮 / β-フェランドレン / 紫外線 / 酸化 / 化学的防御 / 病原菌 / 精油

Outline of Final Research Achievements

This study reveals for the first time that β-phellandrene, which is abundant in Abies sachalinensis bark, is efficiently transformed into oxidation products such as cryptone under the influence of near-ultraviolet light, oxygen, and temperature, and may be involved in enhancing the antifungal activity against A. sachalinensis hosted pathogens. In addition, slow but similar oxidation reactions were also observed in standing trees.
These results strongly support the hypothesis that conifers efficiently produce defensive compounds using the natural environment, and are very important for elucidating the ecological role of terpenes abundant in A. sachalinensis bark. The findings are very important for clarifying the chemo-ecological role of terpenoids in conifers.

Free Research Field

樹木成分学

Academic Significance and Societal Importance of the Research Achievements

針葉樹の樹皮に豊富な樹脂（松ヤニの類）には、かさぶたの様に傷害部を保護する役割が知られている。一方、樹脂を構成するテルペン類には、菌や昆虫などに対して生物活性を示す成分が多数報告されているが、混合状態にある樹脂の防御機能に着目した研究は極めて少ない。本研究で、“針葉樹は自然環境を利用して効率的に防御物質を生成している”という仮説を検証することで、針葉樹の生存戦略における樹脂の生態的役割の一端を明らかにすると同時に、針葉樹の化学的な防御能力を最大限に利用した精油の新規変換・利用技術の開発に大きく貢献できる。