A Rise in ROS and EPS Production: New Insights into the Trichodesmium erythraeum Response to Ocean Acidification

• Published in: Journal of Phycology
• Main Authors: Wu, Shijie, Mi, Tiezhu, Zhen, Yu, Yu, Kaiqiang, Wang, Fuwen, Yu, Zhigang
• Other Authors: Mock, T., Ministry of Science and Technology of the People's Republic of China, National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Ocean acidification
• Online Access: http://dx.doi.org/10.1111/jpy.13075; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jpy.13075; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jpy.13075

The diazotrophic cyanobacterium Trichodesmium is thought to be a major contributor to the new N in parts of the oligotrophic, subtropical, and tropical oceans. In this study, physiological and biochemical methods and transcriptome sequencing were used to investigate the influences of ocean acidification (OA) on Trichodesmium erythraeum ( T. erythraeum ). We presented evidence that OA caused by CO 2 slowed the growth rate and physiological activity of T. erythraeum . OA led to reduced development of proportion of the vegetative cells into diazocytes which included up‐regulated genes of nitrogen fixation. Reactive oxygen species (ROS) accumulation was increased due to the disruption of photosynthetic electron transport and decrease in antioxidant enzyme activities under acidified conditions. This study showed that OA increased the amounts of (exopolysaccharides) EPS in T. erythraeum , and the key genes of ribose‐5‐phosphate (R5P) and glycosyltransferases ( Tery_3818 ) were up‐regulated. These results provide new insight into how ROS and EPS of T. erythraeum increase in an acidified future ocean to cope with OA‐imposed stress.