三角褐指藻的油体建成及调控机制的研究

Microalgae, as the main primary productivity on earth, have high photosynthetic efficiency. The development of marine microalgae industry can make full use of saline tidal flats and other non-arable land resources. Oil-producing microalgae have great application prospects in the fields of bait, health care, renewable energy, etc. Oil bodies (OBs) are the major cellular organelles for the storage of neutral lipids. As a dynamic organelle, OB controls many biological processes, however, little is known about the molecular components determining its biogenesis and development. In this study, the model marine diatom Phaeodactylum tricornutum with high lipid content and high growth rate will be used to explore the regulation mechanisms of oil body. The ultrastructural features of algae OB will be examined through molecular cell biology approaches including fluorescence staining, fluorescent protein tag, immunofluorescence labeling and immuno-electron microscopy. OBs will be isolated and purified, then protein composition and posttranslational modifications will be identified by proteomic analysis. The biological functions of identified proteins involving in the construction of OBs will be determined. The related genes will be cloned and analyzed by combination of fluorescent protein tag, overexpression and RNAi strategy, together with the analysis of lipid transfer. We hope to promote understanding of biogenesis and developmental mechanism of microalgal OBs, and the directional distribution of cellular lipid. The results of our study will shed light on the potential relationship between OB development and lipid accumulation, thus providing a theoretical basis and new ideas for the improvement of the lipid-producing efficiency of microalgae.

微藻光合效率高，是地球上的主要初级生产力，发展海洋微藻产业可充分利用盐碱滩涂等非耕国土资源。富油微藻在饵料、医药保健、可再生能源等领域具有巨大开发应用前景。油体作为微藻胞内储存脂质的主要场所，控制着很多生理生化过程,然而对微藻油体如何建成及调控机制等问题仍亟待深入研究。本研究拟对具有较高脂质含量的海洋硅藻模式藻种三角褐指藻的油体调控机制展开探索。通过荧光染色、荧光蛋白标记、免疫荧光及电镜等细胞生物学手段，明晰油体的超微结构特征。分离纯化油体，通过蛋白组学分析油体的蛋白成分及蛋白修饰等信息。对发现的涉及油体建成的重要蛋白，克隆其基因，通过基因表达调控元件预测分析、荧光蛋白标记、超表达及RNAi等手段，分析其表达调控机制。研究结果将可提升对微藻油体的发生机制的认知，阐释油体发生与脂质累积潜势的关系，为微藻的脂质代谢调控及种质改良提供理论依据和新的思路。

微藻光合效率高，是地球上的主要初级生产力，发展海洋微藻产业可充分利用盐碱滩涂等非耕国土资源。富油微藻在饵料、营养保健、可再生能源等诸多领域具有巨大开发应用前景。油体作为微藻胞内储存脂质的主要场所，控制着很多生理生化过程，然而对微藻油体如何建成及调控机制等问题仍亟待深入研究。本项目对具有较高脂质含量的微藻代表藻种三角褐指藻和微拟球藻的油体调控机制展开了探索。建立了分离高纯度微藻油体组分的方法, 通过蛋白组学分析了油体的结构蛋白及酶的组成。通过荧光染色、荧光蛋白标记、免疫荧光及电镜等细胞生物学手段，明晰了油体的超微结构特征以及油体与其他亚细胞结构的相互作用。鉴定了油体中涉及脂质转运和累积的一些关键蛋白的功能及表达调控机制。初步揭示了油体发生与脂质累积潜势的关系，并通过调控获得了微藻油体的胞外分泌的突破性进展。研究成果提升了对微藻油体的发生机制的认知、油体发生与脂质累积潜势的关系，为微藻的脂质代谢调控及种质改良提供了理论依据和新的思路。同时，本项目获得的工程藻株可为推动微藻资源高值化利用提供支持。