[All-postdocs] Bioseminar - Junkun Ren

[Ana Velez]

Woods Hole Oceanographic Institution
Biology Department Seminar

Thursday, September 11, 2025 - 12:00 pm
Redfield Auditorium

Junkun Ren
MIT-WHOI Joint Program Student

Interpreting the Seasonal Succession of Prochlorococcus and Synechococcus Near Bermuda
Observations have revealed a seasonal succession of picocyanobacteria at the Bermuda Atlantic Time-series Station (BATS) linked to the deep, late winter mixing. The Synechococcus population increases, and the Prochlorococcus population declines, during the period of mixing, high nitrate supply, and low light intensity (DuRand et al, 2001). Characterization of Prochlorococcus reveals that, curiously, nitrate using types increase in abundance and comprise a larger proportion of Prochlorococcus during the summer when nitrate is low and are almost absent in the mixing period when nitrate is high (Berube et al., 2016), opposite to the dynamics of Synechococcus. We use a trait-based model to explore the possible mechanisms that lead to this observed succession. The model resolves Synechococcus and two Prochlorococcus types, with ammonium and nitrate supply and light input. The seasonal succession between Synechococcus and Prochlorococcus not only reflects their size-dependent differences in nutrient affinity and maximum growth rate, more importantly, our study suggests that different limitations by nitrogen resources and incident light between Prochlorococcus and Synechococcus are the key for the asynchronized abundance fluctuations between them and the observed pattern in the proportion of nitrate-using Prochlorococcus types. Moreover, additional costs on the growth rate for nitrate utilization allow for a more evident pattern.

For questions, contact:

Ana Maria Velez
Biology Pre-Award Administrative Associate
Ph: 508-289-2334
[signature_1005462319]

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