Time-resolved carotenoid profiling and transcriptomic analysis reveal mechanism of carotenogenesis for astaxanthin synthesis in the oleaginous green alga Chromochloris zofingiensis

作者：Yu Zhang, Meicheng Shi, Xuemei Mao, Yaping Kou, Jin Liu · 发表于：Biotechnology for Biofuels · 年份：2019 · DOI：10.1186/s13068-019-1626-1 · 被引用次数：79 · 研究领域：Algal biology and biofuel production、Antioxidant Activity and Oxidative Stress、Photosynthetic Processes and Mechanisms

Abstract Background Chromochloris zofingiensis is emerging as an industrially relevant alga given its robust growth for the production of lipids and astaxanthin, a value-added carotenoid with broad applications. Nevertheless, poor understanding of astaxanthin synthesis has limited engineering of this alga for rational improvements. Results To reveal the molecular mechanism underlying astaxanthin accumulation in C. zofingiensis , here we conducted an integrated analysis by combining the time-resolved transcriptomes and carotenoid profiling in response to nitrogen deprivation (ND). A global response was triggered for C. zofingiensis to cope with the ND stress. Albeit the little variation in total carotenoid content, individual carotenoids responded differentially to ND: the primary carotenoids particularly lutein and β-carotene decreased, while the secondary carotenoids increased considerably, with astaxanthin and canthaxanthin being the most increased ones. The carotenogenesis pathways were reconstructed: ND had little effect on the carbon flux to carotenoid precursors, but stimulated astaxanthin biosynthesis while repressing lutein biosynthesis, thereby diverting the carotenoid flux from primary carotenoids to secondary carotenoids particularly astaxanthin. Comparison between C. zofingiensis and Haematococcus pluvialis revealed the distinctive mechanism of astaxanthin synthesis in C. zofingiensis . Furthermore, potential bottlenecks in astaxanthin synthesis were identified an...