Abstract
Polyunsaturated aldehydes (PUAs) are organic compounds mainly produced by diatoms, after cell wounding. These compounds are increasingly reported as teratogenic for species of grazers and deleterious for phytoplanktonic species, but there is still scarce information regarding concentration ranges and the composition of PUAs in the open ocean. In this study, we analyzed the spatial distribution and the type of aldehydes produced by the large-sized (>10 μm) phytoplankton in the Atlantic Ocean surface. Analyses were conducted on PUAs released after mechanical disruption of the phytoplankton cells, referred to here as potential PUAs (pPUAs). Results show the ubiquitous presence of pPUA in the open ocean, including upwelling areas, as well as oligotrophic gyres. Total pPUA concentrations ranged from zero to 4.18 pmol from cells in 1 L. Identified PUAs were heptadienal, octadienal and decadienal, with heptadienal being the most common (79% of total stations). PUA amount and composition across the Atlantic Ocean was mainly related to the nitrogen:phosphorus ratio, suggesting nutrient-driven mechanisms of PUA production. Extending the range of trophic conditions considered by adding data reported for productive coastal waters, we found a pattern of PUA variation in relation to trophic status.
Highlights
Phytoplankton species produce a plethora of bioactive compounds [1]
Longhurst [23] proposed a subdivision of the ocean based on the above-mentioned water characteristics. This biogeographical regionalization of the Atlantic Ocean constitutes a useful tool for describing and comparing the potential PUAs (pPUAs) distributions obtained in this wide sampling area
We extended the trophic gradient of this study by including the published and unpublished data of phytoplankton samples collected in marine coastal areas (Figure 4). pPUA concentrations ranged from pM to micromole (Adriatic Sea and Shallow Bay) concentrations
Summary
A group of these chemicals are the polyunsaturated aldehydes (PUAs), an oxylipin-type compound commonly produced by marine diatoms [2]. PUAs from diatoms have been found to be highly reactive [3], but the nature and ecological significance of these compounds remain largely unknown. PUAs are produced after lipoxidation of intracellular polyunsaturated fatty acids (PUFAs), mainly. Processes producing the disruption of phytoplankton cells are viral infection, grazing or/and cell lysis during senescence [7,8]. Its content and derived compounds, such as these PUAs, are released into the surrounding medium. In the vicinity of the broken cell, the released PUAs create microzones, where they react with other dissolved chemicals and interact with the neighboring organisms
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
