Global gene expression of Prochlorococcus ecotypes in response to changes in nitrogen availability.

TitleGlobal gene expression of Prochlorococcus ecotypes in response to changes in nitrogen availability.
Publication TypeJournal Article
Year of Publication2006
AuthorsTolonen, AC, Aach, J, Lindell, D, Johnson, ZI, Rector, T, Steen, R, Church, GM, Chisholm, SW
JournalMol Syst Biol
Date Published2006
KeywordsBacterial Proteins, Carbon, Carrier Proteins, Ecology, Energy Metabolism, Gene Expression Profiling, Gene Expression Regulation, Bacterial, Nitrogen, Oceans and Seas, Operon, Photosystem II Protein Complex, PII Nitrogen Regulatory Proteins, Prochlorococcus, Sigma Factor, Species Specificity, Transcription Factors, Water Microbiology

Nitrogen (N) often limits biological productivity in the oceanic gyres where Prochlorococcus is the most abundant photosynthetic organism. The Prochlorococcus community is composed of strains, such as MED4 and MIT9313, that have different N utilization capabilities and that belong to ecotypes with different depth distributions. An interstrain comparison of how Prochlorococcus responds to changes in ambient nitrogen is thus central to understanding its ecology. We quantified changes in MED4 and MIT9313 global mRNA expression, chlorophyll fluorescence, and photosystem II photochemical efficiency (Fv/Fm) along a time series of increasing N starvation. In addition, the global expression of both strains growing in ammonium-replete medium was compared to expression during growth on alternative N sources. There were interstrain similarities in N regulation such as the activation of a putative NtcA regulon during N stress. There were also important differences between the strains such as in the expression patterns of carbon metabolism genes, suggesting that the two strains integrate N and C metabolism in fundamentally different ways.

Alternate JournalMol. Syst. Biol.
PubMed ID17016519
PubMed Central IDPMC1682016