Photoprotective acclimation of size-fractionated natural assemblages of phytoplankton at various optical depths in the Indian sector of the Southern Ocean
Photoprotective acclimation of size-fractionated natural assemblages of phytoplankton at various optical depths in the Indian sector of the Southern Ocean
复制标题
南大洋印度区不同光学深度浮游植物大小分级自然组合的光保护驯化
DOI：
10.1007/s00300-014-1527-5
复制
发表时间：
2014
期刊：
影响因子：
1.7
通讯作者：
and Satoru Taguchi
中科院分区：
文献类型：
--
作者：
Motokawa;S.;Hiroshi Hattori;Hiroshi Sasaki;and Satoru Taguchi
混合层中的浮游植物在被输送到海洋表层时暴露于越来越多的光照下。浮游植物的自然组合的光保护反应可以不同的群落结构。我们调查的光保护驯化和叶黄素循环色素的大小分级的天然浮游植物组合在南大洋的印度部门在南半球夏季。我们通过从大量样品中的浓度减去<20 μ m组分中的浓度，以及通过从<20 μ m组分中的浓度减去<2 μ m组分中的浓度，分别估算了微米级组分（> 20 μ m）和纳米级组分（2 - 20 μ m）中浮游植物色素的浓度。在混合层的三个光学深度和48小时甲板孵化太阳光合有效辐射和紫外线辐射下的叶黄素循环色素硅藻黄质（DD）和硅藻黄质（DT）的比例的变化进行了测定。在混合层（DD + DT）/Chlain（百分比变异系数> 67%）和甲板培养瓶中在可变光照条件下（> 75%的时间变异）对于微米级分的大的变化表明比对于纳米级分更高的光保护驯化潜力。DT/（DD + DT）的减少与混合层的光学深度（MLD）的增加表明，在混合层中的光可用性的较大变化可能会预测较低的DT/（DD + DT）的值在表面上，无论细胞的大小。
Phytoplankton in the mixed layer is exposed to increasing levels of light when transported to the surface layer of the ocean. The photoprotective response of natural assemblages of phytoplankton can differ among community structures. We investigated photoprotective acclimation and xanthophyll cycle pigments in size-fractionated natural phytoplankton assemblages during the austral summer in the Indian sector of the Southern Ocean. We estimated concentrations of phytoplankton pigments in the micro-size fractions (>20 μm) and nano-size fractions (2–20 μm) by subtracting concentrations in the <20 μm fractions from concentrations in the bulk samples, and by subtracting concentrations in the <2 μm fractions from concentrations in the <20 μm fractions, respectively. Changes in the ratios of the xanthophyll cycle pigments diadinoxanthin (DD) and diatoxanthin (DT) were determined at three optical depths in the mixed layer and during 48 h deck incubations under solar photosynthetically available radiation and ultraviolet radiation. Large variations in (DD + DT)/Chlain the mixed layer (percent coefficient of variation >67 %) and in deck incubation bottles under variable light conditions (>75 % of the temporal variation) for the micro-size fractions suggest a higher potential for photoprotective acclimation than for the nano-size fractions. Decreases in DT/(DD + DT) with increases in the optical depth of the mixed layer (ζMLD) suggest that larger variations in light availability in the mixed layer might predict lower values of DT/(DD + DT) at the surface, regardless of cell size.