Departments of Biology and Chemistry, Western Washington University, Bellingham, Washington, USA.
Departments of Biology and Marine and Coastal Science, Western Washington University, Bellingham, WA, USA.
J Chem Ecol. 2024 Jun;50(5-6):290-298. doi: 10.1007/s10886-024-01496-9. Epub 2024 Apr 22.
Diatoms are key primary producers across marine, freshwater, and terrestrial ecosystems. They are responsible for photosynthesis and secondary production that, in part, support complex food webs. Diatoms can produce phytochemicals that have transtrophic ecological effects which increase their competitive fitness. Polyunsaturated aldehydes (PUAs) are one class of diatom-derived phytochemicals that are known to have allelopathic and anti-herbivory properties. The anti-herbivory capability of PUAs results from their negative effect on grazer fecundity. Since their discovery, research has focused on their production by pelagic marine diatoms, and their effects on copepod egg production, hatching success, and juvenile survival and development. Few investigations have explored PUA production by the prolific suite of benthic marine diatoms, despite their importance to coastal trophic systems. In this study, we tested eight species of benthic diatoms for the production of the bioactive PUAs 2,4-heptadienal, 2,4-octadienal, and 2,4-decadienal. Benthic diatom species were isolated from the Salish Sea, an inland sea within the North Pacific ecosystem. All species were found to be producers of at least two PUAs in detectable concentrations, with five species producing all three PUAs in quantifiable concentrations. Our results indicate that production of PUAs from Salish Sea benthic diatoms may be widespread, and thus these compounds may contribute to benthic coastal food web dynamics through heretofore unrecognized pathways. Future studies should expand the geographic scope of investigations into benthic diatom PUA production and explore the effects of benthic diatoms on benthic consumer fecundity.
硅藻是海洋、淡水和陆地生态系统中关键的初级生产者。它们负责光合作用和次级生产，部分支持复杂的食物网。硅藻可以产生具有跨营养级生态效应的植物化学物质，从而提高其竞争适应性。多不饱和醛（PUAs）是一类已知具有化感和抗草食性的硅藻衍生植物化学物质。PUAs 的抗草食性能力源于它们对食草动物繁殖力的负面影响。自发现以来，研究主要集中在海洋浮游硅藻的生产及其对桡足类动物卵产量、孵化成功率以及幼体存活和发育的影响上。尽管底栖海洋硅藻对沿海营养系统很重要，但很少有研究探索它们产生 PUA 的情况。在这项研究中，我们测试了来自北太平洋生态系统内内陆海——萨利什海的 8 种底栖硅藻产生生物活性 PUA（2,4-庚二烯醛、2,4-辛二烯醛和 2,4-癸二烯醛）的能力。所有物种都被发现以可检测浓度产生至少两种 PUA，其中 5 种物种以可量化浓度产生所有三种 PUA。我们的结果表明，来自萨利什海底栖硅藻的 PUA 生产可能很普遍，因此这些化合物可能通过迄今为止尚未被认识到的途径对底栖沿海食物网动态产生影响。未来的研究应扩大对底栖硅藻 PUA 生产的地理范围的调查，并探索底栖硅藻对底栖消费者繁殖力的影响。
