HYPERSALINE SOIL SUPPORTS A DIVERSE COMMUNITY OF DUNALIELLA (CHLOROPHYCEAE)1
HYPERSALINE SOIL SUPPORTS A DIVERSE COMMUNITY OF DUNALIELLA (CHLOROPHYCEAE)1
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DOI：
10.1111/j.1529-8817.2010.00886.x
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发表时间：
2010-10-01
影响因子：
2.9
通讯作者：
Henley, William J.
中科院分区：
文献类型：
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作者：
Buchheim, Mark A.;Kirkwood, Andrea E.;Henley, William J.
在美国俄克拉荷马州的大盐原（GSP）进行了微生物多样性调查，对大量的绿色嗜盐杜氏藻进行了研究。GSP是一个大的（类似65平方公里）盐坪极端的时间和空间波动的盐度和温度。虽然鞭毛虫嗜盐杜氏藻在世界范围内很常见，但几乎所有的培养菌株都来自主要水生而不是陆生的盐水栖息地。不同的GSP杜氏藻菌株表现出三种形态型：一个主要的运动形式，一个运动形式与一个突出的palmelloid阶段（nonmotile，粘液丰富），和一个palmelloid形式与一个弱运动阶段。所有具有广泛的最适盐度远低于典型的原位盐度在GSP，和两个palmelloid菌株生长以及在淡水中的高盐介质。分子系统发育和进化分析表明，来自GSP（以及美国大盆地的两个相似栖息地）的杜氏藻与D。绿色特奥多尔。但其系统发育多样性超过了来自水生栖息地的现有全球分离物。此外，主要陆生栖息地的菌株表现出统计学上更高的核苷酸取代率比主要水生杜氏藻类群的同源性。我们假设，动态极端盐渍土生境可能会选择不同的和更多样化的杜氏藻谱系比更稳定的咸水栖息地。我们还建议杜氏藻作为一个易于处理的微生物模型，在原位测试的进化和地理假说。
Numerous isolates of the green halophile Dunaliella were studied as part of a survey of microbial diversity at the Great Salt Plains (GSP) in Oklahoma, USA. The GSP is a large (similar to 65 km2) salt flat with extreme temporal and spatial fluctuations in salinity and temperature. Although the flagellate halophile Dunaliella is common worldwide, nearly all cultured isolates are from saline habitats that are primarily aquatic rather than primarily terrestrial. The diverse GSP Dunaliella strains exhibit three morphotypes: a predominantly motile form, a motile form with a prominent palmelloid phase (nonmotile, mucilage rich), and a palmelloid form with a weakly motile phase. All had broad salinity optima well below typical in situ salinities at the GSP, and two of the palmelloid isolates grew as well in freshwater as in highly saline media. Molecular phylogenetic and evolutionary analyses revealed that Dunaliella from the GSP (and two similar habitats in the Great Basin, USA) are allied with D. viridis Teodor. but possess phylogenetic diversity in excess of existing global isolates from aquatic habitats. In addition, isolates from primarily terrestrial habitats exhibit statistically higher rates of nucleotide substitution than the phylogenetically homogeneous set of primarily aquatic Dunaliella taxa. We hypothesize that dynamically extreme saline soil habitats may select for different and more diverse Dunaliella lineages than more stable saline aquatic habitats. We also propose Dunaliella as a tractable microbial model for in situ testing of evolutionary and phylogeographic hypotheses.