羊草种群地下芽库动态过程中植物激素与碳代谢调控机理的研究

The formation and output of the below-ground population of meristems (bud banks) plays a fundamental role in plant population regeneration, and its composition is very sensitive to environmental changes. Also, the size of the bud banks has a strong influence on the net primary productivity of grassland ecosystems. However, it has so far not clear about the endogenous mechanisms of how signal substances and carbon metabolism regulate the bud banks dynamics even though the role of bud banks in the above-mentioned process is closely related to the regulation of signal substances and carbon metabolism in it. L. chinensis, a typical rhizome species that grow in heterogeneous habitats in Songnen grassland is chosen as the main experimental material to explore the variation of plant hormones and carbon metabolism process in the below-ground bud bank dynamics, and to define the function and mechanism of how those signal substances and carbon metabolism regulate the reproduction of the below-ground bud bank. In the input and output processes of the bud bank, we obtain the endogenous regulatory evidence of the size growth of the bud bank by investigating the discipline of the regulatory functions and the response level of plant hormones, and try to find out the least carbon stocks in the key approach of carbon metabolism that determine the bud bank outputting and locating by study the distribution pattern of those important components generated during the fructan metabolism process. As a result of this research, the endogenous regulatory mechanism and the Physiological Ecology significance of under-ground bud bank clone will bring to light.

植物地下芽库的形成与输出是植物种群持续更新的关键过程,其组成对环境变化十分敏感，并且植物地下芽库数量的消长具有强烈影响草地生态系统净初级生产力的重要潜能。地下芽库在上述过程中的作用与芽库组织中信号物质及碳代谢过程的调控作用密切相关。但这些物质对地下芽库的调控功能目前知之甚少，它们对芽库动态过程调控的内源机理迄今尚不清楚。本项目拟在松嫩草地异质生境背景下，以典型根茎禾草羊草种群为主要实验物种，研究其地下芽库动态过程中植物激素和碳代谢过程的变化规律，明确信号物质和碳代谢对地下芽库繁殖过程的调控功能与作用机理；在芽库的输入与输出过程中，通过研究植物激素调控功能及响应水平的变化规律，获得增加芽库储量的内源调控证据；通过研究果聚糖代谢重要组成的分布格局，获得决定芽库输出与定位时关键碳代谢途径中最低碳储量需求的证据，从而揭示植物种群无性繁殖的内源调控机理和地下芽库无性繁殖习性的生理生态学意义。

植物种群地下芽库的输入输出是植物种群持续更新的关键过程，环境变化对其组成分布影响十分敏感，其组成的数量消长具有强烈影响草地生态系统净初级生产力的重要潜能。本项目通过调查羊草种群地下芽库的动态过程，发现并证实了羊草种群地下芽库各个组成的功能；明确了羊草地下芽库营养繁殖的时空年度格局；确定了响应环境变化最为敏感的芽库组成；提出了羊草种群地下芽库适应环境变化的生长模型。本项目分析了芽库组成中不同植物激素的积累和分布，发现游离的Zeatin、IAA、GA3和ABA均参与了羊草种群地下芽库动态过程的调控作用。其中Zeatin 和 IAA是最初参与根茎顶芽的生长调控的重要激素组成，GA3和ABA在芽库的中后期参与了控制节长的调控作用。我们进行了羊草种群多糖结构的研究，发现羊草中的多糖属于菊糖型结构家族；分析了羊草地下芽库中果聚糖代谢组成的积累和分布，研究结果表明不同生境羊草地下芽库组成在不同的发育阶段有不同的代谢途径，对芽库的输出有重要的调控作用。