Cristi Antonia, Deppeler Stacy, Saint-Macary Alexia, Marriner Andrew, Latasa Mikel, Law Cliff S, Gutiérrez-Rodríguez Andrés
National Institute of Water and Atmospheric Research, 301 Evans Bay Parade, Hataitai, Wellington 6021, New Zealand.
Department of Marine Science, University of Otago, 310 Castle Street, Dunedin 9016, New Zealand.
J Plankton Res. 2025 Jun 15;47(4):fbaf023. doi: 10.1093/plankt/fbaf023. eCollection 2025 Jul-Aug.
and are key phytoplankton taxa in the Southern Ocean that have different bloom magnitude and phenology, reflecting their differing physiological traits. Here, we investigate the physiological response of sp. and colony-forming to warmer and high irradiance conditions using chemostat experiments under low light/low temperature (LL/LT) and high light/high temperature (HL/HT). C:N and C:Chl ratios increased under HL/HT in both species, whereas the sp. Si:C ratio showed no significant variation between treatments despite Si:N being 1.4-fold higher under HL/HT. The colony to a single-cell ratio exhibited a 2.3-fold increase under HL/HT but with no change in the size of individual cells. On the contrary, sp. cell size decreased 1.3-fold without affecting cellular silica content. DMSPt:C and DMS:C increased in both species under HL/HT with no effect of treatment on DMSPt:DMS for either species. Primary pigment markers for taxonomic identification were unaffected by treatment, but pigments in the xanthophyll cycle increased under HL/HT with higher concentrations in sp. and a higher rate of epoxidation in Results indicate a greater tolerance in to increased irradiance and warming than previously described, suggesting that it may be competitive with sp. under conditions usually associated with diatom dominance.
[物种名称1]和[物种名称2]是南大洋中的关键浮游植物类群，它们具有不同的水华规模和物候特征，反映了其不同的生理特性。在此，我们利用恒化器实验，在低光/低温（LL/LT）和高光/高温（HL/HT）条件下，研究了[物种名称1]和形成群体的[物种名称2]对温暖和高辐照度条件的生理响应。在HL/HT条件下，两个物种的C:N和C:Chl比率均升高，而[物种名称1]的Si:C比率在不同处理之间没有显著变化，尽管在HL/HT条件下Si:N高出1.4倍。[物种名称2]的群体与单细胞比率在HL/HT条件下增加了2.3倍，但单个细胞的大小没有变化。相反，[物种名称1]的细胞大小减小了1.3倍，而细胞硅含量不受影响。在HL/HT条件下，两个物种的DMSPt:C和DMS:C均增加，且处理对两个物种的DMSPt:DMS均无影响。用于分类鉴定的主要色素标记不受处理影响，但叶黄素循环中的色素在HL/HT条件下增加，[物种名称1]中的浓度更高，[物种名称2]中的环氧化速率更高。结果表明，[物种名称1]对辐照度增加和变暖的耐受性比之前描述的更强，这表明在通常与硅藻占主导地位相关的条件下，它可能与[物种名称2]具有竞争力。
