Seasonal Gene Expression and the Ecophysiological Implications of Toxic <i>Microcystis aeruginosa</i> Blooms in Lake Taihu

Published on 2018-09-14T15:34:49Z (GMT) by
Harmful cyanobacterial blooms represent an increasing threat to freshwater resources globally. Despite increased research, the physiological basis of how the dominant bloom-forming cyanobacteria, <i>Microcystis</i> spp., proliferate and then maintain high population densities through changing environmental conditions is poorly understood. In this study, we examined the transcriptional profiles of the microbial community in Lake Taihu, China at 9 stations sampled monthly from June to October in 2014. To target <i>Microcystis</i> populations, we collected metatranscriptomic data and mapped reads to the <i>M. aeruginosa</i> NIES 843 genome. Our results revealed significant temporal gene expression patterns, with many genes separating into either early or late bloom clusters. About one-third of genes observed from <i>M. aeruginosa</i> were differentially expressed between these two clusters. Conductivity and nutrient availability appeared to be the environmental factors most strongly associated with these temporal gene expression shifts. Compared with the early bloom season (June and July), genes involved in N and P transport, energy metabolism, translation, and amino acid biosynthesis were down-regulated during the later season (August to October). In parallel, genes involved in regulatory functions as well as transposases and the production of microcystin and extracellular polysaccharides were up-regulated in the later season. Our observation indicates an eco-physiological shift occurs within the <i>Microcystis</i> spp. transcriptome as cells move from the rapid growth of early summer to bloom maintenance in late summer and autumn.

Cite this collection

Tang, Xiangming; Krausfeldt, Lauren E.; Shao, Keqiang; LeCleir, Gary R.; Stough, Joshua M. A.; Gao, Guang; et al. (2018): Seasonal

Gene Expression and the Ecophysiological

Implications of Toxic Microcystis aeruginosa Blooms

in Lake Taihu. ACS Publications. Collection.