Exudation Mechanism of Tree Sap

树液的渗出机制

• 批准号: 10306010
• 负责人: TERAZAWA Minoru
• 金额: $ 16万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10306010/
• 关键词: Tree Sap; Sap Exudation Mechanisms; Shirakamba (Betula); Root Pressures; Water Distribution; Transpiration; Osmotic Pressure; Water Pumping Proteins; 水分分布; シラカンバ; Betula; Birch; タンパク質; フラボノイド配糖体

Sap exudation : The period of the starting point of the sap exudation of birch trees coinsides with that the earth temperatures become above 0℃. The amount of the sap exudated in the one season corelates with the atomospheric temperatures and the change in the amount of sap exudated within a day corelates with the changes in atomospheric temperatures. Production in the leaves in a summer influences the amount of sap exudation in the following spring.Water distribution : The sap in the tracheids disappears gradually towards winter and disappear completely in the period just before the sap exudation starts by the repetition of freezing of the xylem and its re-freezing. The recovery of the cavitation seems to be derived by the pressures in the roots. Actually, the swelling of the roots during the sap exudation process was observed. The process of the refilling of the sap in the tracheids of the xylem was photographically recorded by Cryo-SEM techniques. The osmotic pressures in the sap of xylem tracheids and the function of the water pumping proteins in roots and trunks are the next targets to be investigated.

树干液流：桦树树干液流开始的时间与地温达到0℃以上的时间相吻合。一个季节的汁液分泌量与气温有关，一天内汁液分泌量的变化与气温的变化有关。水分分布：管胞中的树液在冬季逐渐消失，并在树液分泌开始之前的一段时间内完全消失，这是由于木质部的反复冻结和再冻结。空化的恢复似乎是由根部的压力引起的。实际上，在汁液分泌过程中观察到根的膨胀。用冷冻扫描电镜（Cryo-SEM）技术，动态地记录了树液在木质部管胞中的再填充过程。木质部管胞汁液中的渗透压以及根和树干中的泵水蛋白的功能是下一个要研究的目标。