ROS Induce ?-Carotene Biosynthesis Caused by Changes of Photosynthesis Efficiency and Energy Metabolism in Dunaliella salina Under Stress Conditions.

ABSTRACT: The unicellular alga Dunaliella salina is regarded as a promising cell factory for the commercial production of ?-carotene due to its high yield of carotenoids. However, the underlying mechanism of ?-carotene accumulation is still unclear. In this study, the regulatory mechanism of ?-carotene accumulation in D. salina under stress conditions was investigated. Our results indicated that there is a significant positive correlation between the cellular ROS level and ?-carotene content, and the maximum quantum efficiency (F _v /F _m ) of PSII is negatively correlated with ?-carotene content under stress conditions. The increase of ROS was found to be coupled with the inhibition of F _v /F _m of PSII in D. salina under stress conditions. Furthermore, transcriptomic analysis of the cells cultivated with H₂O₂ supplementation showed that the major differentially expressed genes involved in ?-carotene metabolism were upregulated, whereas the genes involved in photosynthesis were downregulated. These results indicated that ROS induce ?-carotene accumulation in D. salina through fine-tuning genes which were involved in photosynthesis and ?-carotene biosynthesis. Our study provided a better understanding of the regulatory mechanism involved in ?-carotene accumulation in D. salina, which might be useful for overaccumulation of carotenoids and other valuable compounds in other microalgae.

SUBMITTER: Xi Y 

PROVIDER: S-EPMC7844308 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature