Journal Article

Diel transcriptional response of a California Current plankton microbiome to light, low iron, and enduring viral infection

Allen, E. E., McCrow, J. P., Moniruzzaman, M., Kolody, B. C., Fontanez, K. M., Delong, E. F., Aylward, F. O., Moustafa, A., Worden, A. Z., Chavez, F. P., Allen, A. E., Allen, L. Zeigler, Scholin, C. A.

2019

Overview

Phytoplankton and associated microbial communities provide organic carbon to oceanic food webs and drive ecosystem dynamics. However, capturing those dynamics is challenging. Here, an in situ, semi-Lagrangian, robotic sampler profiled pelagic microbes at 4 h intervals over ~2.6 days in North Pacific high-nutrient, low-chlorophyll waters. We report on the community structure and transcriptional dynamics of microbes in an operationally large size class (>5 μm) predominantly populated by dinoflagellates, ciliates, haptophytes, pelagophytes, diatoms, cyanobacteria (chiefly Synechococcus) , prasinophytes (chiefly Ostreococcus) , fungi, archaea, and proteobacteria. Apart from fungi and archaea, all groups exhibited 24-h periodicity in some transcripts, but larger portions of the transcriptome oscillated in phototrophs. Periodic photosynthesis-related transcripts exhibited a temporal cascade across the morning hours, conserved across diverse phototrophic lineages. Pronounced silica:nitrate drawdown, a high flavodoxin to ferredoxin transcript ratio, and elevated expression of other Fe-stress markers indicated Fe-limitation. Fe-stress markers peaked during a photoperiodically adaptive time window that could modulate phytoplankton response to seasonal Fe-limitation. Remarkably, we observed viruses that infect the majority of abundant taxa, often with total transcriptional activity synchronized with putative hosts. Taken together, these data reveal a microbial plankton community that is shaped by recycled production and tightly controlled by Fe-limitation and viral activity.

• Publisher: Nature Publishing Group UK,Oxford University Press,Nature Publishing Group
• Subject: 45 / 631/326/171/1878 / 704/158/2446/2447 / 704/47 / Archaea / Biomedical and Life Sciences / California / Chlorophyll / Ciliates / Ciliophora - genetics / Ciliophora - metabolism / Ciliophora - radiation effects / Ciliophora - virology / Communities / Community structure / Cyanobacteria / Diatoms - genetics / Diatoms - metabolism / Diatoms - radiation effects / Diatoms - virology / Dinoflagellates / Dinoflagellida - genetics / Dinoflagellida - metabolism / Dinoflagellida - radiation effects / Dinoflagellida - virology / Drawdown / Ecology / Ecosystem dynamics / Environmental Sciences & Ecology / Evolutionary Biology / Ferredoxin / Flavodoxin / Food Chain / Food chains / Food webs / Fungi / Gene expression / Haptophyta - genetics / Haptophyta - metabolism / Haptophyta - radiation effects / Haptophyta - virology / Iron / Iron - metabolism / Life Sciences / Light effects / Marine ecosystems / Marine microorganisms / Markers / Microbial activity / Microbial Ecology / Microbial Genetics and Genomics / Microbiology / Microbiomes / Microbiota / Microorganisms / Nutrient dynamics / Oceans and Seas / Organic carbon / Periodicity / Photosynthesis / Phytoplankton / Phytoplankton - genetics / Phytoplankton - metabolism / Phytoplankton - radiation effects / Phytoplankton - virology / Plankton / Plankton - genetics / Plankton - metabolism / Plankton - radiation effects / Plankton - virology / Silica / Silicon dioxide / Transcription / Transcription, Genetic / Transcriptomes / Virus Physiological Phenomena / Viruses - genetics / Windows (intervals)