Open AccessGlobal gene expression of Prochlorococcus ecotypes in response to changes in nitrogen availability
Author(s) -
Tolonen Andrew C,
Aach John,
Lindell Debbie,
Johnson Zackary I,
Rector Trent,
Steen Robert,
Church George M,
Chisholm Sallie W
Publication year - 2006
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.1038/msb4100087
Subject(s) - george (robot) , medical school , library science , biology , history , medicine , art history , computer science , medical education
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 ( F v / F m ) 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.