虾青素因具有极强的抗氧化性而备受关注，养殖红球藻是获取天然虾青素的最佳途径。红球藻规模化养殖过程中，如何避免户外强光胁迫引起的光抑制和提高虾青素含量是该产业亟待解决的问题。经过大量筛选，我们发现小分子有机物丙三醇（GL）可以明显缓解红球藻光抑制并提高其虾青素含量，那么GL的作用机制是什么？这对于户外红球藻养殖具有重要指导意义却未见报道。为此，本项目通过研究红球藻光合电子传递、光合系统损伤与修复过程、光抑制防御途径对GL的响应规律，阐明GL缓解光抑制的方式和分子机制；同时对比研究外施GL后，红球藻GL的分解转化途径、光合/呼吸/脂肪酸合成等初生代谢过程及虾青素合成途径关键基因/蛋白的表达及产物的含量变化，结合转录、蛋白质及代谢组学数据明确GL促进虾青素积累的过程和分子机制。本项目从新的角度探寻提高虾青素产量的途径，为通过人工调控或遗传改良提高红球藻抗光抑制能力和虾青素含量提供理论依据。

The super-antioxidant astaxanthin has wide application and bright future in many fields. Haematococcus pluvialis is the optimal source for natural astaxanthin production. In outdoor large-scale cultures of H. pluvialis, alleviating photoinhibition of cells caused by strong light and enhancing astaxanthin content have always been urgent problems to be solved. And our previous study indicates that exogenous glycerol can protect cells against photoinhibition, as well as accelerate astaxanthin accumulation in H. pluvialis. While the mechanisms of photoinhibition alleviation and astaxanthin content enhancement by adding glycerol in H. pluvialis has not been clarified. In this project, in order to analyze molecular mechanisms of photoinhibition alleviation by adding glycerol, the changes in state of photosynthetic electron transport chain, photodamage and photorepair of photosystems, photoinhibition defense pathway after adding glycerol will be determined. Moreover, the effects of exogenous glycerol on key genes/proteins expression and products contents in glycerol metabolism, primary metabolisms (photosynthesis, respiration and fatty acid metabolism) and astaxanthin biosynthesis pathway will be analyzed. Meanwhile, combined with thanscriptomic, proteomic and metabonomic approaches, the mechanisms of astaxanthin content enhancement by adding glycerol in H. pluvialis will be clarified. The results of this project could provide theoretical supports in artificial regulation or genetic engineering methods, for improving the tolerance to photoinhibitory stress and capacity of astaxanthin biosynthesis in H. pluvialis.