Alteromonas macleodii breaches the diatom frustule triggering protoplast emergence and programmed necrosis-like death in Thalassiosira rotula
En palabras de los autores
Abstract Diatom-bacteria interactions drive biogeochemical fluxes at the base of the marine food-web. Although bacteria are increasingly recognised as important drivers of algal mortality, the diversity of algicidal strategies remains understudied. Here we show that Alteromonas macleodii , a recurrent member of Thalassiosira rotula ’s microbiome, breaches the diatom’s silica frustule, inducing >95% of cells to emerge from their shells within 72 h, exposing protoplasts to lysis and exploitation. Whilst protoplast formation was induced by diverse bacteria, A. macleodii uniquely caused population-wide collapse, used here to characterise this diatom stress response. Dual transcriptomics indicated the presence of a programmed necrosis-like cell death pathway in diatoms underpinning T. rotula ’s terminal morphological change, alongside upregulation of bacterial motility, chemotaxis and opportunistic metabolism. These findings reveal a potent algicidal strategy, recasting A. macleodii as an antagonist that exploits diatom mortality for its own benefit, removes the ballast provided by their frustules and thus reshapes oceanic carbon cycling.
Apareció: lunes, 28 de septiembre. Nature Communications. Revista con revisión por pares.