In recent years, Phaeocystis globosa blooms have occurred with high frequency and large geographic range, causing huge losses in the marine aquaculture industry, and even threatening the safety of nuclear power plant cooling systems. Colony formation is an ecological competitive strategy of P. globosa and the main form during the algal blooms. Therefore, the study on the colony-formation mechanism of P. globosa is of great scientific and social significance. In this study, we analyzed the changes of monosaccharide composition and gene expression of polysaccharide metabolism during the colony formation of P. globosa. Results showed that the content of arabinose was higher in the colony-forming strain of P. globosa than in the solitary-cell strain, as well as the expression levels of the genes related to the glycan synthesis base on arabinose. Additionally, exogenous arabinose could promote the colony formation of P. globosa. Therefore, arabinose was presumed to play a key role in the colony-formation of P. globosa. This study will improve our understanding of the formation mechanism of P. globosa colonies, as well as provide a scientific basis for studying the P. globosa blooms on the formation mechanism and the measures of prevention and control.

Phaeocystis globosa, colony formation, arabinose, monosaccharide composition, polysaccharide metabolism