Potential for heightened sulfur metabolic capacity in coastal, subtropical microalgae : [DATASETS]

The activities of microalgae support nutrient cycling that helps to sustain aquatic and terrestrial ecosystems. Most microalgal species, especially those from the subtropics, are genomically uncharacterized. Here we report the isolation and genomic characterization of 22 microalgal species from subtropical coastal regions belonging to multiple clades and three from temperate areas. Halotolerant strains including Halamphora, Dunaliella, Nannochloris, and Chloroidium comprised the majority of these isolates. The subtropical-based microalgae contained arrays of methyltransferase, pyridine nucleotide-disulfide oxidoreductase, abhydrolase, cystathionine synthase, and small-molecule transporter domains present at high relative abundance. We found that genes for sulfate transport, sulfotransferase, and glutathione S-transferase activities were especially abundant in subtropical, coastal microalgal species and halophytic species in general. Our metabolomics analyses indicate lineage- and habitat-specific sets of biomolecules implicated in niche-specific biological processes. This work effectively expands the collection of available microalgal genomes by ∼50%, and the generated resources provide perspectives for studying halophyte adaptive traits.

微藻的生命活动支撑养分循环，助力水生与陆地生态系统的稳态维持。目前多数微藻物种，尤其是亚热带来源的类群，其基因组特征尚未得到解析。本研究报道了22株分离自亚热带沿海区域的微藻物种的分离与基因组表征，这些物种隶属于多个演化支，此外还包含3株温带来源的微藻。本次分离株中，桥弯藻属（Halamphora）、杜氏藻属（Dunaliella）、拟小球藻属（Nannochloris）以及绿球藻属（Chloroidium）等耐盐菌株占多数。亚热带来源的微藻基因组中，甲基转移酶、吡啶核苷酸-二硫键氧化还原酶、AB水解酶、胱硫醚合酶与小分子转运蛋白结构域的相对丰度显著偏高。研究发现，与硫酸盐转运、磺基转移酶及谷胱甘肽S-转移酶活性相关的基因在亚热带沿海微藻以及广义的盐生物种中尤为丰富。代谢组学分析显示，不同谱系与生境的微藻拥有特异性的生物分子谱，这些分子参与生态位特异性的生物学过程。本研究将现有可获取的微藻基因组数据集扩充约50%，所生成的研究资源为盐生植物适应性性状的相关研究提供了全新视角。