Brown algae are multicellular photosynthetic stramenopiles that colonize marine rocky shores worldwide. Ectocarpus sp. Ec32 has been established as a genomic model for brown algae. Here we present the genome and metabolic network of the closely related species, Ectocarpus subulatus Kützing, which is characterized by high abiotic stress tolerance. Since their separation, both strains show new traces of viral sequences and the activity of large retrotransposons, which may also be related to the expansion of a family of chlorophyll-binding proteins. Further features suspected to contribute to stress tolerance include an expanded family of heat shock proteins, the reduction of genes involved in the production of halogenated defence compounds, and the presence of fewer cell wall polysaccharide-modifying enzymes. Overall, E. subulatus has mainly lost members of gene families down-regulated in low salinities, and conserved those that were up-regulated in the same condition. However, 96% of genes that differed between the two examined Ectocarpus species, as well as all genes under positive selection, were found to encode proteins of unknown function. This underlines the uniqueness of brown algal stress tolerance mechanisms as well as the significance of establishing E. subulatus as a comparative model for future functional studies.

褐藻是多细胞的光合作用层茎，遍布全球海洋多岩石的海岸。赤果sp。Ec32已被确立为褐藻的基因组模型。在这里，我们介绍了密切相关的物种，Ectocarpus subulatus的基因组和代谢网络库琴（Kützing）具有非生物胁迫耐受性高的特点。由于它们的分离，两种菌株都显示出新的病毒序列和大型逆转录转座子的活性，这也可能与叶绿素结合蛋白家族的扩展有关。怀疑有助于胁迫耐受性的其他特征包括热休克蛋白家族的扩大，参与卤代防御化合物生产的基因的减少以及细胞壁多糖修饰酶的减少。总体而言，枯草芽孢杆菌主要失去了在低盐度下调的基因家族成员，并保留了在相同条件下上调的基因家族成员。然而，两种被检食的赤芝之间有96％的基因差异物种，以及正选择的所有基因，被发现编码未知功能的蛋白质。这突出了棕色藻类胁迫耐受机制的独特性，以及建立枯草大肠杆菌作为未来功能研究的比较模型的重要性。