山东半岛潮间带大型海藻鼠尾藻对UV-B辐射增强的性别差异响应及分子调控机制研究

The ozone layer thinning has been one of the most conspicuous issues at the background of global climate change. Consequently, more and more ultraviolet radiations, especially Ultraviolet-B radiation with severe biological damage effects, reach the surface of the earth. Enhanced UV-B radiation have been reported to have significant biological and ecological effects on ecosystem. Sargassum thunbergii, inhabiting in the intertidal, is daily exposed to extreme changes in environmental conditions. In addition, it is a typical dioecism macroalgae. Hence, we chose Sargassum thunbergii as tested organism to study the effect of enhanced UV-B radiation on intertidal macroalgae. This study intends 1) to disclose the sex-specific response of growth and reproduction, 2) to discover the changes of physiology, biochemistry and cell structure between male and female and 3) to survey the diverse effect on DNA transcription and mRNA translation of marcoalage when exposed to increasing radiation. According to different changes at the growth, reproduction, physiology, biochemistry, cellular and molecular level between male and female of Sargassum thunbergii, we would clarify the different response characteristics and the molecular mechanism to supplemental UV-B. Our goals are to provide the theoretical basis for life history strategy and adaptation mechanisms of dioecism macroalgae, and to develop a better understanding about the key role of macroalgae in regulating global climate change.

臭氧层减薄是当今最引人注目的全球变化现象之一，而且全球性的臭氧层侵蚀和破坏仍在日渐加重。臭氧层的减薄使得到达地面的紫外线，尤其是对生物具严重损伤作用的UV-B的辐射增强，从而对全球产生明显的环境生态学效应。大型海藻是海洋生态系统中对UV-B辐射增强最直接的响应者，其中鼠尾藻既是潮间带大型海藻群落的优势种，又是雌雄异株海藻的代表种。因此本项目以UV-B辐射增强为影响因子，选用鼠尾藻为材料，开展以下三方面的研究工作。1、鼠尾藻雌雄藻体生长和生殖过程对UV-B辐射增强的差异响应。2、鼠尾藻雌雄藻体生理、生化和细胞特征对UV-B辐射增强的差异响应。3、鼠尾藻雌雄藻体转录和翻译对UV-B辐射增强的分子差异响应。从生长、生殖、生理、生化、细胞和分子层面系统阐明鼠尾藻雌雄藻体对UV-B辐射增强的差异响应和分子调控机制。为准确估计大型海藻在调节全球变化中的作用和揭示雌雄藻体生活史对策及适应机制提供依据。

臭氧层减薄是当今最引人注目的全球变化现象之一，而且全球性的臭氧层侵蚀和破坏仍在日渐加重。臭氧层的减薄使得到达地面的紫外线，尤其是对生物具严重损伤作用的UV-B的辐射增强，从而对全球产生明显的环境生态学效应。大型海藻是海洋生态系统中对UV-B辐射增强最直接的响应者，其中鼠尾藻既是潮间带大型海藻群落的优势种，又是雌雄异株海藻的代表种。因此本项目以UV-B辐射增强为影响因子，选用鼠尾藻为研究对象，综合应用生理学、转录组学和蛋白质组学等研究方法，系统研究了鼠尾藻对UV-B辐射增强的响应特征及分子机制;在此基础上，从细胞、生理、生化和代谢等各个层次系统阐明了鼠尾藻雌雄藻体对UV-B辐射增强的性别差异响应特征，发现了鼠尾藻雌雄藻体对UV-B辐射增强的差异响应主要体现在两大基础代谢途径-碳代谢和氮代谢，并从转录和代谢水平探索了影响性别差异响应的关键候选基因和代谢产物的调控作用；此外，拓展研究了鼠尾藻雌雄藻体附生微生物群落结构和多样性对UV-B辐射增强的差异响应特征，揭示了UV-B辐射增强对附生微生物相互作用及其功能的影响机制，从附生微生物的视角进一步阐明了鼠尾藻对UV-B辐射增强的性别差异响应特征和机制；最后，以潮间带雌雄异株大型海藻-坛紫菜为比较研究对象，从细胞、生长、生理、转录和代谢等各个层次系统阐明了坛紫菜的雌雄差异及对UV-B辐射增强的差异响应特征及机制，为更准确揭示雌雄异株大型海藻对UV-B辐射增强的性别差异响应特征提供了有价值参考。以上研究的开展为准确评估大型海藻在调节全球变化中的作用和揭示雌雄藻体生活史对策及适应机制提供依据。