High antioxidant capability interacts with respiration to mediate two Alexandrium species growth exploitation of photoperiods and light intensities
High antioxidant capability interacts with respiration to mediate two Alexandrium species growth exploitation of photoperiods and light intensities
复制标题
高抗氧化能力与呼吸相互作用，介导两种亚历山大藻对光周期和光强度的生长利用
DOI：
10.1016/j.hal.2018.12.008
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发表时间：
2019-02-01
期刊：
影响因子：
6.6
通讯作者：
Li, Gang
中科院分区：
文献类型：
--
作者：
Hui, Wang;Zhang, Bowen;Li, Gang
光驱动浮游植物进行光合作用，因此生活栖息地的浮游植物必须根据季节、纬度、深度和混合事件利用不同的光照水平和暴露持续时间。研究了小型亚历山大藻（类似于）40 μ m(3) 生物体积）和大型链状亚历山大藻（类似于）9300 μ m(3) 生物体积）的比较生长、生理和生化成分，以及全球范围内广泛传播的沿海有毒赤潮甲藻，对光周期矩阵（光：暗、8:16、16:8 和 24:0）和生长光的响应辐照度。较小的 A. minutum 在整个生长光照水平的较短光周期下生长得更快，而较大的 A. catenella 在最低光照水平下的较长光周期下生长最快。光系统II功能主要对光周期长度内的瞬时生长光水平做出反应，而基于细胞生物体积的呼吸、抗氧化能力以及细胞组成对光周期持续时间的反应比对光水平的反应更大。这些复杂的光生理反应分解为生长速率与细胞抗氧化活性和暗呼吸之间的线性相关性，表明呼吸为细胞抗氧化系统提供能量，有利于细胞的生长。这些结果表明，亚历山大藻物种在不同光周期内对光照水平的生长反应因物种而异，并且可能随细胞大小而变化。与之前的结果一起，这对通过将不同光周期应用于不同类群的研究得出的对光强度的生理反应的荟萃分析外推提出了警告，因为不同的类群对光周期和光强度表现出不同的、甚至相反的生长反应。
Light drives phytoplankton photosynthesis, so phytoplankton in their living habitats must exploit variable light levels and exposure durations, depending upon seasons, latitudes, depths and mixing events. Comparative growth, physiology and biochemical compositions were explored for the small Alexnadrium minutum ((similar to)40 mu m(3) biovolume) and large Alexandrium catenella ((similar to)9300 mu m(3) biovolume), globally wide spread coastal toxic red tide dinoflagellates, responding to a matrix of photoperiods (Light:Dark, 8:16, 16:8 and 24:0) and growth light ir-radiances. Smaller A. minutum grew faster under shorter photoperiods across growth light levels, while larger A. catenella grew fastest under longer photoperiods at the lowest applied light level. Photosystem II function responded largely to the instantaneous growth light level across photoperiod lengths, while the cell biovolume-based respiration, antioxidant capacity as well as cell composition responded more to photoperiod duration than to light level. These complex photophysiological responses resolved into linear correlations between growth rate versus cellular antioxidant activity and versus dark respiration, indicating that respiration energizes cellular antioxidant systems to benefit the growth of the cells. These results show the growth responses of Alexandrium species to light levels across photoperiods vary with species, and possibly with cell size. Together with previous results this puts a note of caution on meta-analytical extrapolations of physiological responses to light intensity derived from studies applying different photoperiods to different taxa, because different taxa show differential, even opposite growth responses to photoperiods and light intensities.