PT - JOURNAL ARTICLE AU - Markel Gómez-Letona AU - Javier Arístegui AU - Nauzet Hernández-Hernández AU - María Pérez-Lorenzo AU - Xosé Antón Álvarez-Salgado AU - Eva Teira AU - Marta Sebastián TI - Surface productivity gradients govern changes in abundance and physiological status of deep ocean prokaryotes across the tropical and subtropical Atlantic AID - 10.1101/2022.06.20.496789 DP - 2022 Jan 01 TA - bioRxiv PG - 2022.06.20.496789 4099 - http://biorxiv.org/content/early/2022/06/20/2022.06.20.496789.short 4100 - http://biorxiv.org/content/early/2022/06/20/2022.06.20.496789.full AB - Prokaryotes represent a major fraction of marine biomass and play a key role in the global carbon cycle. We studied the vertical profiles (from surface down to the bathypelagic realm) of abundance, cytometric signatures, and activity of prokaryotic communities along a productivity gradient in the subtropical and tropical Atlantic to assess whether there is a vertical linkage between surface productivity regimes and deep ocean prokaryotic communities. We found that latitudinal changes in the vertical patterns of cytometric variables were coupled with surface productivity: higher prokaryotic abundances and viabilities, and smaller cell sizes were observed below highly productive surface waters, an effect reaching down to the bathypelagic layer. On the contrary, leucine uptake rates in deep waters showed no clear relationship with surface productivity. Changes in resource and energy allocation to growth vs. maintenance in hostile environments, cell-size-dependent metabolic requirements and variability in leucine to carbon conversion may all be part of the array of factors involved in controlling prokaryotic activity patterns that were measured. Our work adds to the recent findings that highlight the importance of vertical connectivity for prokaryotic communities in the dark ocean.Competing Interest StatementThe authors have declared no competing interest.