Rhythms of lysis: viral regulation of prokaryotic turnover across diel cycles

Diel rhythms structure microbial activity in the ocean, yet the role of viral lysis in driving short-term community dynamics remains poorly understood. Here, we combined dilution experiments, high-resolution microbiome sampling, and extracellular ribosome sequencing to investigate diel virus–host interactions in the South China Sea. Viral lysis accounted for an average of 41% of Synechococcus and 24% of heterotrophic bacterial mortality at night. Overall, 74% of amplicon sequence variants (ASVs) showed lysis signals, with many displaying significant diel fluctuations. Notably, rare taxa comprised a large fraction of diel-responsive ASVs, indicating high turnover among low-abundance populations. Synechococcales exhibited tightly coupled nighttime peaks in abundance and lysis, while SAR11 and Flavobacteriales showed delayed lysis after late-day growth. In addition, virus-mediated mortality had a stronger influence on metabolically active and diel-responsive ASVs. These findings highlight ..., , # Rhythms of lysis: viral regulation of prokaryotic turnover across diel cycles

Dataset DOI: [10.5061/dryad.4qrfj6qrg](https://doi.org/10.5061/dryad.4qrfj6qrg)

## Description of the data and file structure

Environmental_metadata.xlsx provides station, date and time, depth, latitude and longitude, hydrographic variables (temperature, salinity, dissolved oxygen), fluorescence, photosynthetically active radiation (PAR), nutrient concentrations (NO₂⁻, NO₃⁻, PO₄³⁻, SiO₃²⁻), and abundances of heterotrophic bacteria, Synechococcus and Prochlorococcus.Additional worksheets summarize the acrophases (peak times) of diel periodicity in cell abundances for different microbial groups at SEATS and SS1.

ASV_metadata.xlsx contains 16S rRNA amplicon sequence variant (ASV) tables and taxonomy; rows are ASVs and columns are samples for the rDNA~cell~, rRNA~cell~ and rRNA~ext~ fractions.

Dilution experiment data.xlsx reports cell abundances of heterotrophic bacteria and Synechococcus for each dilution...,