Title | Bacterial Quorum-Sensing Signal Arrests Phytoplankton Cell Division and Impacts Virus-Induced Mortality |
Publication Type | Journal Article |
Year of Publication | 2021 |
Authors | Pollara SB, Becker JW, Nunn BL, Boiteau R, Repeta D, Mudge MC, Downing G, Chase D, Harvey EL, Whalen KE |
Secondary Authors | McMahon K |
Journal | mSphere |
Volume | 6 |
Pagination | e00009–21, /msphere/6/3/mSph.00009–21.atom |
ISSN | 2379-5042 |
Keywords | rcc1731 |
Abstract | Interactions between phytoplankton and heterotrophic bacteria fundamentally shape marine ecosystems by controlling primary production, structuring marine food webs, mediating carbon export, and influencing global climate. Phytoplankton-bacterium interactions are facilitated by secreted compounds; however, linking these chemical signals, their mechanisms of action, and their resultant ecological consequences remains a fundamental challenge. The bacterial quorumsensing signal 2-heptyl-4-quinolone (HHQ) induces immediate, yet reversible, cellular stasis (no cell division or mortality) in the coccolithophore Emiliania huxleyi; however, the mechanism responsible remains unknown. Using transcriptomic and proteomic approaches in combination with diagnostic biochemical and fluorescent cell-based assays, we show that HHQ exposure leads to prolonged S-phase arrest in phytoplankton coincident with the accumulation of DNA damage and a lack of repair despite the induction of the DNA damage response (DDR). While this effect is reversible, HHQ-exposed phytoplankton were also protected from viral mortality, ascribing a new role of quorum-sensing signals in regulating multitrophic interactions. Furthermore, our data demonstrate that in situ measurements of HHQ coincide with areas of enhanced micro- and nanoplankton biomass. Our results suggest bacterial communication signals as emerging players that may be one of the contributing factors that help structure complex microbial communities throughout the ocean. |
URL | https://msphere.asm.org/content/6/3/e00009-21 |
DOI | 10.1128/mSphere.00009-21 |