Springtime photoinhibition constrains regeneration of evergreen coniferous trees
| Project/Area Number |
17K19301
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Forestry and Forest Products Science, Applied aquatic science, and related fields
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| Research Institution | Forest Research and Management Organization |
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Principal Investigator |
Kitao Mitsutoshi 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 (60353661)
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| Project Period (FY) |
2017-06-30 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
Fiscal Year 2019: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2018: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
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| Keywords | 光阻害 / 常緑針葉樹 / 開葉 / 春の光阻害 / 糖 / デンプン / トドマツ / 遺伝子発現 / メタボローム解析 / 林床稚樹 / 生理生態学 |
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| Outline of Final Research Achievements |
We investigated the underlying mechanism of springtime photoinhibition in evergreen conifer species, by conducting chlorophyll fluorescence measurements, RNA-sequence data and metabolomic analyses in seedlings of Sakhalin fir (Abies sachalinensis) around budbreak. We observed springtime photoinhibition just before budbreak, indicated by a temporal decrease in the maximum photochemical efficiency of photosystem II (Fv/Fm) . Based on RNA-sequence data analysis, genes related to starch breakdown and sugar export, and oxidative stress were induced. Metabolic analysis suggests an imbalance in C/N relationship (excessive carbon to nitrogen) based on increases in 2-oxoglutaric acid and 3-phosphoglyceric acid in the photoinhibited leaves. Increased sugar concentration, which is needed for breaking bud dormancy and new leaf development, might induce photoinhibition via photosynthetic down-regulation.
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| Academic Significance and Societal Importance of the Research Achievements |
遅霜の害として知られる常緑針葉樹の晩霜害は、新葉の開葉直前に感受性が高く、既存の葉が障害を受けることを特徴とする。晩霜害は晴天日の早朝に放射冷却によって生じることから、低温の影響だけでなく、強光による光阻害の関与が疑われてきた。クロロフィル蛍光測定により、開葉の直前に既存の葉の光阻害感受性が一時的に上昇することが明らかとなった。また、開葉直前のデンプン分解による糖濃度の一時的な上昇が、光合成のダウンレギュレーションを引き起こし、光阻害感受性を増加させることが示唆された。これらの研究成果は地球温暖化による開葉の早期化が、常緑針葉樹の晩霜害へ与える影響を予測する際の科学的知見となる。
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Report
(4 results)
Research Products
(7 results)
