Study on overwintering mechanism of dormant buds of trees for sustainable production of woody biomass

为了了解落叶松休眠芽的越冬机理，对落叶松休眠芽的器官外冷冻和内气味释放进行了研究。低温扫描电子显微镜研究表明，原始细胞在零下的温度下部分脱水，原始细胞中的水分保持在深度过冷状态。在该组织中，有几种碳水化合物的积累是主要成分，如平尼醇和蔗糖。然而，很难解释原始组织的深度过冷能力所产生的高耐寒性仅由主要碳水化合物的积累决定。在落叶松休眠芽中，可以研究过冷促进物质等次要成分的可能贡献。此外，利用LC-MS/MS进行蛋白质组学分析表明，落叶松休眠芽在释放内气味的3周内，可溶性蛋白质组分只有很小的变化。

In this study, extraorgan-freezing and endodormancy release of larch dormant buds were studied for understanding overwintering mechanism of dormant buds of trees.Cryo-scanning electron microscopic study revealed that primordial cells were partially dehydrated at subzero temperatures and water remaining in primordial cells was kept in the deep supercooling state. In this tissue, accumulation of several carbohydrates such as pinitol and sucrose were detected as major components. However, it is difficult to explain that high freezing tolerance by deep supercooling capability of primordial tissue is determined by accumulation of major carbohydrates alone. Possible contribution of minor components such as supercooling-facilitating substances might be studied in larch dormant buds. In addition, proteomic analysis by using LC-MS/MS showed that only minor changes in soluble protein composition occurred in larch dormant buds within three weeks during endodormancy release.