Universität zu Köln, Biozentrum Köln, Botanisches Institut, Zülpicher Str. 47B, 50674 Köln, Germany.
Protist. 2014 Mar;165(2):123-43. doi: 10.1016/j.protis.2014.01.001. Epub 2014 Jan 17.
No detailed studies have been performed to date on osmotolerance in cryptophytes, although one species, Chroomonas africana, had previously been reported to grow in freshwater as well as seawater. This study focused on osmotolerance in Chroomonas. Growth at different osmolalities and parameters of contractile vacuole function were examined and compared across a high-resolution phylogeny. Two evolutionary lineages in the Chroomonas clade proved to be euryhaline. Ranges of osmotolerance depended not only on osmolality, but also on culture medium. All cryptophytes contained contractile vacuoles. In the euryhaline strain CCAP 978/08 contractile vacuoles could be observed even at an osmolality beyond that of seawater. In addition the cells accumulated floridoside, an osmoprotectant likely originating from the red algal carbohydrate metabolism of the complex rhodoplast. Further evidence for functional contractile vacuoles also in marine cryptophytes was provided by identification of contractile vacuole-specific genes in the genome of Guillardia theta.
迄今为止，尚未对隐甲藻的耐渗性进行详细研究，尽管此前曾有报道称一种名为非洲衣藻的物种既可以在淡水也可以在海水中生长。本研究重点关注衣藻的耐渗性。在高分辨率系统发育中，研究了不同渗透压下的生长情况和收缩泡功能的参数，并进行了比较。衣藻群中的两个进化谱系被证明是广盐的。耐渗性范围不仅取决于渗透压，还取决于培养基。所有隐甲藻都含有收缩泡。在广盐菌株 CCAP 978/08 中，甚至可以在超过海水渗透压的条件下观察到收缩泡。此外，细胞积累了岩藻糖苷，这是一种可能来源于复杂红色藻光合作用碳水化合物代谢的渗透保护剂。在海洋隐甲藻中也发现了具有收缩泡功能的进一步证据，这是通过鉴定基因组中特有的收缩泡基因 Guillardia theta 得出的。
