浒苔是潮间带大型海藻的代表种，具有极强的抗逆性,尤其是对失水胁迫的耐受性。我们前期的研究表明，浒苔的类囊体仅由3-5层的膜松散地垛叠在一起，不存在高等植物的基粒，并且PSI和PSII等复合体驱动的光合电子传递对失水胁迫敏感。然而，这些问题背后的分子机制仍不清楚。为此，本项目以浒苔为研究对象，探究类囊体结构和PSI、PSII等复合体的分布、组成和功能对失水胁迫的响应机制。主要聚焦PSI和PSII等复合体在类囊体膜上的具体定位，解析失水胁迫状态下类囊体的结构变化特征和复合体的分布变化规律；分离不同状态下的PSI和PSII等复合体，分析复合体的蛋白和色素的组成及其对失水胁迫的响应特征；进一步分析复合体的时间分辨荧光光谱特征，阐明不同状态下PSI和PSII等复合体能量传递特征和功能异同。本项目的完成不仅可以丰富我们对浒苔生物学特性的认识，而且有助于我们了解潮间带大型海藻对胁迫环境的适应机制。

Ulva prolifera is a representative species of the intertidal macro-algae which could tolerate various stresses particularly dehydration stress. Our previous study demonstrated that the thylakoid of U. prolifera has 3-5 loosely stacked membranes which lack conventional plant grana. Moreover, photosynthetic electron flows driven by PSI and PSII in U. prolifera are sensitive to dehydration stress. However, the molecule mechanism is still unknown. Therefore, in this program U. prolifera are chosen to deeply investigate the responsive mechanisms of the thylakoid structure and the distribution, composition and function of membrane protein complexes (PSI and PSII) to dehydration stress. We will focus on the distribution of the thylakoid membranes protein complexes and clarify the dynamic flexibility of the thylakoid and the membrane protein complexes under dehydration stress. Moreover, we will purify the thylakoid membrane complexes (PSI and PSII) under different conditions and analyze the compositions (proteins and pigments) and their responses to dehydration stress. In addition, we will further determine the time-resolved fluorescence spectra, and clarify the characteristics of energy transfer and functional differences. The completion of this program will help us to understand not only the special biology of U. prolifera, but also the acclimation mechanisms of the macro-algae to stresses.