高山林线树种分子适应及对林线形成的作用

The hypothesises of "carbon limitation" and "growth limitation" are considered to be better to explain the reason of alpine treeline formation. However,it still remains controversial from the current studies, and it is necessary to further study by using more advanced technology. In this study, based on our study of ecophysiological mechanism of Qilan Mountain treeline foramtion, the transcriptomics of Picea crassifolia at the different altitudes were established with the high-through sequencing technology (Solexa), and the profiles of differential expression at the different altitudes were analyzed with the bioinformatics method; the genes related closly to the growth, such as carbonhydrate metabolism, cell cycle, hormones and so on, were mined, and especially, non-structural carbohydrate (NSC) metabolism related genes were further analyzed; the patterns of these genes were studied in the seedlings of different altitudes under the treatments of simulated cold stresses. Combination with the physiological and biochemical analysis, the mechanism of molecular responses of treeline trees were discussed. Finally, the reason of Qilian Mountain treeline formation were explained at the molecular levels.

高山林线形成的"碳受限"和"生长受限"假说，被认为能从生理生态水平较好的解释林线形成的原因。然而，从现有研究看仍然存在较大争议，亟待利用更先进的手段进一步研究。本研究在对祁连山林线形成的生理生态基础研究的前提下，拟以林线树种青海云杉（Picea crassifolia）为材料，利用高通量转录组测序(Solexa)技术建立青海云杉不同海拔的转录组、应用生物信息学手段高通量分析比较不同海拔的差异表达谱；发掘碳代谢、细胞周期、激素等与生长密切相关的差异表达基因，重点分析与非结构性碳水化合物（NSC）代谢相关基因的表达差异；并通过模拟低温胁迫处理不同海拔种子幼苗，研究这些基因随海拔变化的表达模式，结合相关生理生化分析，探讨林线树种随海拔变化的分子响应机制；最终，从分子水平解释祁连山林线形成的原因。