心材化过程中木质部薄壁细胞代谢活性与心材成分生成机制

为了揭示心材形成过程中木质部薄壁细胞的代谢活性变化及心材成分生成和迁移机制，本研究首先聚焦边材-过渡区-心材木质部薄壁细胞形态、结构以及细胞呼吸作用、酶活性等变化，并结合薄壁细胞代谢活性与其生活环境水分、氧气等关系，明确边材转化为心材过程中薄壁细胞代谢活性减少直至死亡过程及原因。其次，透过边材-过渡区-心材薄壁细胞多酚类成分或生成多酚类物质的前驱体生成过程，分析多酚类成分或生成多酚类物质前驱体的结构，以及多酚类不同物质合成过程或其前驱体合成不同多酚物质的化学反应路径。最后，透过边材-过渡区-心材薄壁细胞与导管、木纤维心材成分的类型和蓄积状态，分析薄壁细胞生成心材成分向周围其它组织，特别是向远离心材成分生成区域的迁移规律。项目致力解答“心材化过程中木质部薄壁细胞代谢活性和心材成分生成机制”前沿课题，为多渠道调控心材形成、例如红木树种的人工培育提供基础科学依据。

In order to reveal the changes of metabolic activity of xylem parenchyma cells, generating and transporting mechanism of heartwood extractives during the process of heartwood formation, the changes of the cell morphology and structure, cellular respiration and enzymatic activity of xylem parenchyma cells in the sapwood-transition zone-heartwood was focused firstly, and the relationship between parenchyma cells metabolic activity and live environment water and oxygen was also considered, so that the process and reason of metabolic activity decrease, even death of parenchyma cells was clarified during the transformation of sapwood into heartwood.Secondly, the structure of polyphenol compositions or their precursor of generating polyphenol substances, and the chemical reaction pathways of biosynthetic course of different phenolic compounds or precursors which generate different polyphenol constituents will be analyzed through the generation process of polyphenol compositions or the precursor of generating polyphenols in the parenchyma cells of sapwood-transition zone-heartwood. Thirdly, transport pathway of heartwood extractives generated from parenchyma cells exuded into adjacent wood tissues, heartwood especially away from transition zone will be investigated, based on the type and accumulation state of parenchyma cells among parenchyma cells, vessels and wood fiber of sapwood- transition zone-heartwood. The “metabolic activity of xylem parenchyma cells and the mechanism of heartwood extractives generating during heartwood formation” as advanced subject will be answered in this project, as well providing basis science reference for regulating and controlling heartwood formation by different ways, for example the artificial cultivation of “Hongmu” tree.