Enhancement of exopolysaccharides production and reactive oxygen species level of Nostoc flagelliforme in response to dehydration

Wu, Shijie; Yu, Kaiqiang; Li, Long; Wang, Lingxia; Liang, Wenyu

Enhancement of exopolysaccharides production and reactive oxygen species level of Nostoc flagelliforme in response to dehydration

2021

Wu, Shijie | Yu, Kaiqiang | Li, Long | Wang, Lingxia | Liang, Wenyu

Nostoc flagelliforme is a remarkable drought-resistant terrestrial cyanobacterium whose exopolysaccharides (EPS) have been found to exert important physiological and ecological functions, and the EPS are known to improve soil physicochemical properties. In this study, we used physiological and molecular methods to investigate the influences of three moisture loss levels on EPS production and the antioxidant system in N. flagelliforme. The aim was to reveal the EPS production mechanism involved in the gene differential expression and antioxidant system of N. flagelliforme in response to drought. Our results showed that EPS contents increased by 13% and 22% after 6-h and 48-h dehydration (6HAD and 48HAD) compared with 4-h rehydration (4HAR), respectively. The same trends were also detected for most EPS synthesis genes, especially glycosyltransferases. Furthermore, the intracellular reactive oxygen species (ROS) levels in N. flagelliforme were generally higher at 6HAD and 48HAD than at 4HAR. Superoxide dismutase (SOD) and peroxidase (POD) activities were restricted in N. flagelliforme under 6HAD and 48HAD compared with 4HAR, but the opposite result was found in catalase (CAT) activity. These results provide a new foundation for understanding the mechanism of EPS accumulation in N. flagelliforme in response to drought.

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