Novel mechanisms of winter xylem dysfunction due to pit aspiration in conifer trees
| Project/Area Number |
17H03825
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Forest science
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
Taneda Haruhiko 東京大学, 大学院理学系研究科(理学部), 准教授 (90403112)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
福田 健二 東京大学, 大学院農学生命科学研究科(農学部), 教授 (30208954)
矢崎 健一 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 (30353890)
|
|---|
| Project Period (FY) |
2017-04-01 – 2021-03-31
|
| Project Status |
Completed (Fiscal Year 2021)
|
| Budget Amount *help |
¥13,390,000 (Direct Cost: ¥10,300,000、Indirect Cost: ¥3,090,000)
Fiscal Year 2020: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2019: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2018: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Fiscal Year 2017: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
|
|---|
| Keywords | 植物生態学 / 乾燥ストレス / 水輸送 / 寒冷地適応 / 木部構造 / 仮道管 / 水ストレス / 植物 / 亜高山帯 / 針葉樹 / 通水コンダクタンス / MRI |
|---|
| Outline of Final Research Achievements |
Winter xylem dysfunction caused by frost drought is a major cause of mortality in subalpine evergreen conifers growing in wind-exposed environments. This study uncovered that the inhibition of stem water transport was caused by sap-freezing-induced pit aspiration as well as the xylem embolism, which is a blockage of xylem tracheids due to entry of air using Abies veitchii dominant species of Japanese subalpine forest. The pit aspiration occurred in a slightly stressed plant in winter and was regained rapidly after the conifers recovered from drought stress in April. Severe xylem embolism was found in a highly dehydrated plant and was repaired slowly by mid-July by refilling the embolized lumen with water.
|
| Academic Significance and Societal Importance of the Research Achievements |
亜高山帯に分布する常緑針葉樹では，森林限界など風衝環境の個体で冬季に茎で深刻な通水阻害が起きる．この原因として，仮道管内部の水が凍結したときに溶け出る気体が融解後に膨らんで仮道管の内腔を塞ぐ現象（凍結融解によるエンボリズム）がであるとされてきた．一方で，実験室内での実験では，凍結融解によるエンボリズムは，直径の太い道管・仮道管ほど弱い水ストレスでも深刻な通水阻害が起きるが，常緑針葉樹は細い仮道管を持ち，凍結融解によるエンボリズムが起こりにくいことが示されている．本研究は，壁孔膜の閉鎖による通水阻害を世界で初めて発見し，こうした野外での測定と実験室での測定における矛盾に合理的な説明を与えた．
|
Report
(5 results)
Research Products
(24 results)
