混合营养型生物具有自养、异养和兼性营养代谢模式，在兼性营养中响应环境变化所采取的营养策略展现了这类生物代谢模式的可塑性。此外，当资源限制时，混合营养型生物代谢模式的转换也是其营养模式高度可塑的重要体现，这对生态系统中食物网结构和功能有着重要影响。然而，目前针对混合营养型生物代谢模式的可塑过程及调控机制尚缺乏深刻认识，而了解该过程中其营养策略的调控途径是解决该科学问题的关键之处。据此，本项目拟结合稳定同位素、细胞显微观察技术及时序多组学分析等研究手段，探究混合营养型棕鞭毛虫在不同代谢模式转换过程中关键资源利用和能量代谢水平的变化，明确该过程中其营养策略的调控途径及关键基因和代谢物的表达特征，最终揭示混合营养型生物代谢模式转换过程的调控机制。本研究不仅对于全面系统地认识混合营养型生物的营养策略和生态功能具有重要意义，同时也为揭示混合营养型生物代谢系统的适应性进化机制提供新思路。

Mixotroph is a kind of microorganism combining autotrophic, heterotrophic, and mixotrophic modes. In mixotrophic mode, their nutritional strategy in response to environmental changes demonstrates the plasticity of metabolic modes. In addition, the change of the metabolic modes in mixotrophic organisms in response to limited resources is also an important embodiment of their highly plastic nutritional modes, which has profound impacts on the structures and functions of the food web in aquatic ecosystem. However, it is still lack of profound understanding of the plastic process of metabolic modes and its regulatory mechanism in mixotrophic organisms. To realize how they regulate nutritional strategy is vital for this scientific issue. Therefore, the present study will use a common mixotrophic organism Ochromonas to conduct the following experiments by stable isotope technique, cell microscopy technique and temporal muti-omics analysis methods. Firstly, the differences in resource utilization and energy metabolism pathway during the changes of metabolic modes in mixotrophic Ochromonas will be analyzed. In addition, the pathways involved in regulating nutritional strategies when Ochromonas changes metabolic modes will be elucidated. And the temporal regulation characteristics of key genes and key metabolites will be identified. Finally, according to these researches, the regulatory mechanism of nutritional strategy in mixotrophs will be revealed. In conclusion, the present study will be of great theoretical significance for comprehensively and systematically understanding metabolic modes and ecological roles of mixotrophs and also provide a new thought for revealing adaptive evolutionary mechanism of metabolic system in mixotrophs.