Publications

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2015
Palenik, B.  2015.  Molecular mechanisms by which marine phytoplankton respond to their dynamic chemical environment. Annual Review of Marine Science, Vol 7. 7:325-340.   10.1146/annurev-marine-010814-015639   AbstractWebsite

Marine scientists have long been interested in the interactions of marine phytoplankton with their chemical environments. Nutrient availability clearly controls carbon fixation on a global scale, but the interactions between phytoplankton and nutrients are complex and include both short-term responses (seconds to minutes) and longer-term evolutionary adaptations. This review outlines how genomics and functional genomics approaches are providing a better understanding of these complex interactions, especially for cyanobacteria and diatoms, for which the genome sequences of multiple model organisms are available. Transporters and related genes are emerging as the most likely candidates for biomarkers in stress-specific studies, but other genes are also possible candidates. One surprise has been the important role of horizontal gene transfer in mediating chemical-biological interactions.

2013
Stuart, RK, Brahamsha B, Busby K, Palenik B.  2013.  Genomic island genes in a coastal marine Synechococcus strain confer enhanced tolerance to copper and oxidative stress. Isme Journal. 7:1139-1149.   10.1038/ismej.2012.175   AbstractWebsite

Highly variable regions called genomic islands are found in the genomes of marine picocyano-bacteria, and have been predicted to be involved in niche adaptation and the ecological success of these microbes. These picocyanobacteria are typically highly sensitive to copper stress and thus, increased copper tolerance could confer a selective advantage under some conditions seen in the marine environment. Through targeted gene inactivation of genomic island genes that were known to be upregulated in response to copper stress in Synechococcus sp. strain CC9311, we found two genes (sync_1495 and sync_1217) conferred tolerance to both methyl viologen and copper stress in culture. The prevalence of one gene, sync_1495, was then investigated in natural samples, and had a predictable temporal variability in abundance at a coastal monitoring site with higher abundance in winter months. Together, this shows that genomic island genes can confer an adaptive advantage to specific stresses in marine Synechococcus, and may help structure their population diversity.