@article{fdi:010067774,
  title = {{M}echanisms of {T}richodesmium demise within the {N}ew {C}aledonian lagoon during the {VAHINE} mesocosm experiment},
  author = {{S}pungin, {D}. and {P}freundt, {U}. and {B}erthelot, {H}. and {B}onnet, {S}ophie and {A}l{R}oumi, {D}. and {N}atale, {F}. and {H}ess, {W}. {R}. and {B}idle, {K}. {D}. and {B}erman-{F}rank, {I}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he globally important marine diazotrophic cyanobacterium {T}richodesmium is abundant in the {N}ew {C}aledonian lagoon (southwestern {P}acific {O}cean) during austral spring/summer. {W}e investigated the cellular processes mediating {T}richodesmium mortality from large surface accumulations (blooms) in the lagoon. {T}richodesmium cells (and associated microbiota) were collected at the time of surface accumulation, enclosed under simulated ambient conditions, and sampled over time to elucidate the stressors and subcellular underpinning of rapid biomass demise (>90% biomass crashed within similar to 24 h). {M}etatranscriptomic profiling of {T}richodesmium biomass, 0, 8 and 22 h after incubations of surface accumulations, demonstrated upregulated expression of genes required to increase phosphorus ({P}) and iron ({F}e) availability and transport, while genes responsible for nutrient storage were downregulated. {T}otal viral abundance oscillated throughout the experiment and showed no significant relationship with the development or demise of the {T}richodesmium biomass. {E}nhanced caspase-specific activity and upregulated expression of a suite of metacaspase genes, as the {T}richodesmium biomass crashed, implied autocatalytic programmed cell death ({PCD}) as the mechanistic cause. {C}oncurrently, genes associated with buoyancy and gas vesicle production were strongly downregulated concomitant with increased production and high concentrations of transparent exopolymeric particles ({TEP}). {T}he rapid, {PCD}-mediated, decline of the {T}richodesmium biomass, as we observed from our incubations, parallels mortality rates reported from {T}richodesmium blooms in situ. {O}ur results suggest that, whatever the ultimate factor, {PCD}-mediated death in {T}richodesmium can rapidly terminate blooms, facilitate aggregation, and expedite vertical flux to depth.},
  keywords = {{NOUVELLE} {CALEDONIE} ; {PACIFIQUE}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {13},
  numero = {14},
  pages = {4187--4203},
  ISSN = {1726-4170},
  year = {2016},
  DOI = {10.5194/bg-13-4187-2016},
  URL = {https://www.documentation.ird.fr/hor/fdi:010067774},
}