青钱柳三萜类化合物的地理变异及其与环境的耦合关系

Cyclocarya paliurus, native to China, is the sole species in its genus and one of rare and endangered plants in China as well. Grown for its fine timber and as a medicinal and ornamental plant, there exists a great development and application prospect for C. paliurus resources. Recently a huge production of tender leaves is required from C. paliurus plantations duo to increasing interest in the use of C. paliurus as a functional food ingredient and/or as traditional Chinese medicine. However, a little information is available on the collection and breeding of C. paliurus superior gene resouces for medical utilization, while no information was reported especially on the interaction of gene × environment, the coupling relation between key secondary metabolite accumulation and environmental factors, as well as the relationship between growth and secondary metobilte accumulation. In this project, a combined technical route of field trials and controlled experiments in the growth chambers is adopted based on the collected resource materials and established plantations of C. paliurus, while some advanced analysis techniques and methods are applied in this research, such as high-performance liquid chromatography and mass spectrometry, sequence related amplified polymorphism (SRAP) markers, differential proteomics etc. The objectives of this present project are to investigate the geographical variation in accumulation of key health-promoting triterpenoids in the leaves of C. paliurus and its coupling relation to environmental factors, to test the carbon/nutrient balance theory, and to reveal the response pathway of triterpenoid compounds to the stimulus of environmental factors and their mechanisms of cell regulation. The results from the research project would provide new information for extensive breeding programmes of C. paliurus which have been initiated to increase the levels of compounds with potential targeted health-promoting substances and for manipulating field growing conditions and optimizing silvicultural system, so that we would preliminarily establish the mechanism and theory of secondary metobilte accumulation which fits in with woody medicinal plants.

青钱柳是我国特有的单种属植物和国家重点保护的濒危植物之一，集药用、保健、材用和观赏价值为一身，具有很高的保护与开发应用前景。目前，关于药用青钱柳优良基因资源收集和选育研究报道很少，特别是关于基因与环境的交互作用、重要次生代谢产物积累与环境间的耦合关系以及与次生代谢产物积累与生长间关系等的研究几乎处于空白状态。本项目以现有收集的青钱柳种质资源和田间试验林为研究材料，采用控制性试验和田间试验相结合的技术路线，应用高效液相色谱和质谱联用、SRAP分子标记、差异蛋白质组学等现代分析技术和方法，探索青钱柳叶中重要三萜类化合物积累的地理变异模式以及与环境因子的耦合关系，验证碳素/营养平衡诱导机制假说，揭示三萜类化合物产生对外界环境刺激的反应途径和细胞调控机制，初步建立符合木本栽培药用植物次生代谢物质积累规律的机制和理论，为药用青钱柳新品种（基因型）筛选及规范化和规模化栽培提供科学依据。

青钱柳（Cyclocarya paliurus）是我国特有的单种属植物及重点保护的濒危植物，具有药用、保健、材用和观赏等多种价值，开发利用的潜在价值极大。三萜类化合物是青钱柳重要的次生代谢产物，具有降糖、降压以及有抗肿瘤、防治心脑血管疾病、提高人体免疫力等多种生物活性功能，因此青钱柳三萜类化合物的地理变异及其与环境的耦合关系具有十分重要的意义。本项目以收集的青钱柳种质资源、田间试验林和青钱柳天然群体为研究材料，采用控制性试验和田间试验相结合的技术路线，应用高效液相色谱和质谱联用等现代分析技术和方法，探索了青钱柳叶中三萜类化合物等次生代谢物质积累的地理变异模式以及与环境因子的耦合关系。现有研究结果表明，青钱柳叶三萜类等化合物含量与种源、光照强度以及叶片采摘时间密切相关；虽然环境因子、青钱柳基因型对叶中三萜类等化合物组分和积累的影响较为复杂，但筛选适宜的种源和优化栽培环境对青钱柳叶中次生代谢物质积累至关重要；青钱柳叶片总三萜地理变异规律，是以东经116°，北纬31°为中心高点，向四周逐渐降低的趋势；树高和地径的生长速率与黄酮和三萜含量间都存在着一定的负相关关系，但与地径生长相比，树高生长与黄酮和三萜含量间的相关性更明显；气候因子和土壤养分对青钱柳生长、黄酮和三萜积累产生了影响，其中以年降雨量、土壤总有机碳（SOC）、交换性钾等的影响较大；青钱柳醇提取物和水提物均有良好的降血糖、降血脂和抗氧化作用，其中，青钱柳三萜酸是其降脂活性部位。通过4年研究，初步建立了符合木本栽培药用植物次生代谢物质积累规律的机制和理论，为药用青钱柳新品种（基因型）筛选及规范化和规模化栽培提供了科学依据。本项目已公开发表论文16篇，其中在被SCI收录的国际刊物上发表8篇，在国内核心刊物上发表8篇；培养研究生6名（其中3名博士）。