【作者】 刘士刚；

【导师】 祖元刚； 于景华；

【作者基本信息】 东北林业大学 ， 植物学， 2005， 硕士

【摘要】 喜树（Camptotheca acuminata）为中国特有树种。本论文利用生理生态学方法及功能蛋白质组学技术研究了喜树幼苗在干旱胁迫下的蛋白质动态及其对干旱逆境的分子生态适应机理。本文以15%PEG₈₀₀₀模拟干旱胁迫条件,研究了不同处理时间下喜树幼苗相对含水量、气孔导度等等生理指标的变化,采用双向电泳与肽质量指纹图谱方法并结合N-端测序鉴定和分析了部分功能蛋白质的动态。 本文研究结果表明:喜树幼苗能够忍耐短时间的15%PEG₈₀₀₀干旱胁迫,但生理严重紊乱,在10%PEG₈₀₀₀干旱胁迫下,喜树碱含量表达上升具有重要的应用意义。喜树幼苗在蛋白质水平上对干旱逆境的生态适应机制包括两个方面,首先是一些干旱诱导蛋白如胚胎发育后期丰富蛋白（Late Embryo Abundant protein LEA）和热激蛋白（Heat shock protein HSP）表达量提高,对于叶肉细胞保持必要的水分和正常的生理代谢功能有重要意义,GTP水解酶与Rubisco活化酶对维持喜树幼苗正常的代谢有着重要的作用。其次是1,5-二核酮糖羧化酶/加氧酶大亚基（Rubisco LSU）以及微管蛋白（Tublin）等通过降解,避免了变性蛋白的自毒作用,有助于提高叶肉细胞水势或抑制气孔开放,从而起到保持水分、适应干旱逆境的作用。更多还原

【Abstract】 Camptotheca acuminata is a tree unique to China. The molecular ecology of drought stress to Camptotheca acuminata seedlings with the theory and method of functional proteomics was systematically studied. The physiological indexes correlative to drought-tolerance were studied in the laboratory, and the expression of total proteins were also detected in the study.We simulated drought stress with 15% PEG8000, and used 2-DE, PMSF. and N-terminal analysis to identify and analyze the dynamic state of some functional proteins. Spraying Camptothecin(CPT) as a microtubule depolymerization agency, we studied the stoma movement of Camptotheca acuminata seedlings under drought stress conditions.Camptotheca acuminata seedlings could tolerate 15% PEGgooo simulated drought stress during short time but the physiology was severe disturbance. CPT content was ascend under 10% PEGgooo drought stress condition that has important application purport. The results indicated that the molecular mechanism of Camptotheca acuminata seedlings adapted to drought stress on the level of protein included two aspects .Firstly, some drought-induced proteins increased expression such as the Late Embryo Abundant protein (Lea protein) and heat shock protein (HSP), which were significant for maintained mesophyll cell water and normal metabolism. GTPase and Rubisco activase had important funcation on metabolism of Camptotheca acuminata seedlings. Secondly, Rubisco LSU and tubulin were degraded for avoiding self-poisonous denatured protein. It could contribute to enhance mesophyll cell water potential and inhibit the stoma open so as to keep water and adapt to drought stress.更多还原