Halotaxis of cyanobacteria in an intertidal hypersaline microbial mat
Halotaxis of cyanobacteria in an intertidal hypersaline microbial mat
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DOI：
10.1111/j.1462-2920.2009.02095.x
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发表时间：
2010-03-01
影响因子：
5.1
通讯作者：
de Beer, Dirk
中科院分区：
文献类型：
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作者：
Kohls, Katharina;Abed, Raeid M. M.;de Beer, Dirk
来自阿布扎比（阿拉伯联合酋长国）的潮间带高盐蓝藻垫在上覆水的盐度变化后的几个小时内表现出其表面颜色的可逆变化。在盐度高于15%时，垫表面为橙红色，在较低盐度时变为深绿色。我们研究了这种现象，使用多相方法，包括变性梯度凝胶电泳，显微镜，高效液相色谱，高光谱成像，吸收光谱，氧微传感器测量和盐度动态建模。根据16S rRNA测序和形态学鉴定，发现微鞘藻的丝状体在盐度降低到15%以下或增加到15%以上时分别向上和向下迁移，导致最上层的颜色变化。迁移发生在光和黑暗中，并可以诱导不同的盐，而不仅仅是NaCl。盐依赖性和独立的物理化学参数，如水活度，氧溶解度，H（2）S，重力和光的影响，被排除在外，表明所观察到的迁移是由于盐胁迫的直接响应。我们建议将这种盐度驱动的蓝藻迁移称为“趋盐性”，这一过程可能在蓝藻在暴露于连续盐度波动的环境中（如滩涂）的生存中发挥至关重要的作用。
P>An intertidal hypersaline cyanobacterial mat from Abu Dhabi (United Arab Emirates) exhibited a reversible change in its surface colour within several hours upon changes in salinity of the overlying water. The mat surface was orange-reddish at salinities above 15% and turned dark green at lower salinities. We investigated this phenomenon using a polyphasic approach that included denaturing gradient gel electrophoresis, microscopy, high-performance liquid chromatography, hyperspectral imaging, absorption spectroscopy, oxygen microsensor measurements and modelling of salinity dynamics. Filaments of Microcoleus chthonoplastes, identified based on 16S rRNA sequencing and morphology, were found to migrate up and down when salinity was decreased below or increased above 15%, respectively, causing the colour change of the mat uppermost layer. Migration occurred in light and in the dark, and could be induced by different salts, not only NaCl. The influence of salinity-dependent and independent physico-chemical parameters, such as water activity, oxygen solubility, H(2)S, gravity and light, was excluded, indicating that the observed migration was due to a direct response to salt stress. We propose to term this salinity-driven cyanobacterial migration as 'halotaxis', a process that might play a vital role in the survival of cyanobacteria in environments exposed to continuous salinity fluctuations such as intertidal flats.