Chemical identification of insect elicitors and their downstream signals toward enhancement of plant functions

Research Project

Project/Area Number	17K07774
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Bioorganic chemistry
Research Institution	Akita Prefectural University
Principal Investigator	Noge Koji 秋田県立大学, 生物資源科学部, 助教 (40423008)
Project Period (FY)	2017-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000) Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2017: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Keywords	情報分子 / 植物ホルモン / ジャスモン酸 / エリシター / オオイタドリ / アミノ酸 / シグナル伝達
Outline of Final Research Achievements	Plants show various defense responses against insect feeding, such as the production of substances that repel herbivores or attract natural enemies. The system, in which the amino acid-derived nitriles are produced from giant knotweed leaves by feeding of the Japanese beetle, found by our group, is different from the known materials in that amino acids accumulation occurs by insect feeding. Using this system, we elucidated the insect-derived component (elicitor) that activates the plant defense responses and explored the possibility of new plant functions associated with insect feeding-inducible amino acids. Although elicitor could not be isolated, it was found that the faeces of the Japanese beetle also contained elicitor, and that plant hardening occurred due to a factor other than the known lignin accumulation.
Academic Significance and Societal Importance of the Research Achievements	エリシターが失活しやすいなど，解決できなかった問題もあり，エリシターの単離には至らなかったが，タンパク質性と低分子性のエリシターを合わせ持つ例はこれまでなく，学術的には，引き続きエリシターの同定を進める価値があると考える．昆虫食害や雑草は，食料生産の観点から，その影響を抑える方向へと研究が進むことが一般的であるが，本研究のように昆虫食害や雑草を食と直結させようとする試みは，他にない特色のある研究になると期待していた．期間内に期待を上回る成果が得られたとは考えていないが，既知とは異なる仕組みで植物が硬くなるといった新しい可能性を見出すことができた点は，今後の発展につながる礎になると考える．