雨生红球藻厚壁孢子形成对虾青素合成的相关基因转录调控的影响机制

Haematococcus pluvialis is the best source of natural astaxanthin known as the "king of the antioxidant", but low efficiency of astaxanthin biosynthesis has become a bottleneck of industry development on producing natural astaxanthin. In various cell morphologies of H. pluvialis, the high-efficient synthesis of astaxanthin often coupled with akinete formation. It was found in our previous study, the astaxanthin synthesis rate when astaxanthin induced at the same time of akinete formation is significantly quicker than that when astaxanthin induced after akinete formation, although the induction conditions are identical. Therefore, there is a complex relation between astaxanthin synthesis and akinete formation. The study on this relation will be a novel entry point for studying on the regulatory of astaxanthin accumulation to explore unknown mechanisms and exploit novel technologies. On the basis of our preliminary studies, the molecular mechanisms of akinete formation will be studied from cell physiology and gene expression in this project. And then, by combined with the expression difference of genes related with astaxanthin synthesis during akinete formation, the influencing mechanism of akinete formation on astaxanthin accumulation will be explored at the level of transcription. This study will not only provide a scientific basis of genetically engineered H. pluvialis for the high-efficient production of natural astaxanthin, and also be an important guide to optimize existing technologs about astaxanthin photoinduction of H. pluvialis, suggesting this project would be greatly significant for the robust development of natural astaxanthin industry.

雨生红球藻是被誉为“抗氧化之王”的天然虾青素的最佳来源，但较低的虾青素合成效率已成为限制该产业发展的瓶颈。该藻具有多种细胞形态，而虾青素高效合成过程常伴随着厚壁孢子的大量形成。申请者发现，诱导条件相同，细胞向厚壁孢子转变的同时开始诱导虾青素合成，其合成效率远高于细胞形成厚壁孢子后的虾青素合成。因此，厚壁孢子形成对虾青素合成存在着极大影响。解析该影响是研究虾青素合成调控机制的全新切入点，有助于挖掘新的调控机制并有望用于新生产工艺的开发。本项目在前期研究基础上，拟从生理生化和基因表达层面，研究厚壁孢子形成的分子机制；进而结合厚壁孢子转变过程中虾青素合成相关基因的表达变化，从基因转录层面来阐明厚壁孢子形成对虾青素合成调控的影响机制。本项目研究不仅为基因工程改造雨生红球藻高产天然虾青素提供科学依据，而且对现有雨生红球藻光诱导合成虾青素工艺优化具有重要的指导意义，可促进天然虾青素产业的蓬勃发展。

雨生红球藻是被誉为“抗氧化之王”的天然虾青素的最佳来源，但较低的虾青素合成效率已成为限制该产业发展的瓶颈。该藻具有多种细胞形态，而虾青素高效合成过程常伴随着厚壁孢子的大量形成。申请者发现，诱导条件相同，细胞向厚壁孢子转变的同时开始诱导虾青素合成，其合成效率远高于细胞形成厚壁孢子后的虾青素合成。因此，厚壁孢子形成对虾青素合成存在着极大影响。通过本项目的研究，明确了细胞厚壁孢子转变的规律，以及转变过程与虾青素积累的协同关系，构建了细胞形态转变和虾青素相关基因的共调控网络，挖掘了雨生红球藻厚壁孢子转变影响虾青素积累的关键基因和调控因子。进而比较分析了厚壁孢子转变与虾青素积累二者的全局表达网络，综合分析基因表达之间的协同性，在转录组层面阐述了厚壁孢子转变对虾青素合成调控的影响机制，得到了“厚壁孢子转变过程中叶绿素代谢是影响虾青素积累的关键因素，并与虾青素积累有着明显的协同关系”的这一重要结论，进一步证实该结论在其他的细胞形态转变中同样具有普适性。本项目从雨生红球藻红球藻形态转变这一全新切入点研究了虾青素合成调控机制，挖掘了新的调控机制并用于新生产工艺的开发，不仅为基因工程改造雨生红球藻高产天然虾青素提供科学依据，而且对现有雨生红球藻光诱导合成虾青素工艺优化具有重要的指导意义，可促进天然虾青素产业的蓬勃发展。