Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
Sci Rep. 2019 Mar 4;9(1):3336. doi: 10.1038/s41598-019-39860-5.
Microalgae are currently considered one of the most promising resources for biofuel production, aquaculture feedstock and new pharmaceuticals. Among them, green algae of the genus Tetraselmis are extensively studied for their lipid accumulation in nutrient-starvation conditions. In this paper, we present the full-transcriptome of Tetraselmis suecica and differential expression analysis between nitrogen-starved and -repleted conditions (at stationary phase) focusing not only on lipid metabolism but giving new insights on nutrient starvation responses. Transcripts involved in signal transduction pathways, stress and antioxidant responses and solute transport were strongly up-regulated when T. suecica was cultured under nitrogen starvation. On the contrary, transcripts involved in amino acid synthesis, degradation of sugars, secondary metabolite synthesis, as well as photosynthetic activity were down-regulated under the same conditions. Among differentially expressed transcripts, a polyketide synthase and three lipoxygenases (involved in the synthesis of secondary metabolites with antipredator, anticancer and anti-infective activities) were identified, suggesting the potential synthesis of bioactive compounds by this microalga. In addition, the transcript for a putative nitrilase, enzyme used in nitrile bioremediation, is here reported for the first time for T. suecica. These findings give new insights on T. suecica responses to nutrient starvation and on possible biotechnological applications for green algae.
微藻目前被认为是生物燃料生产、水产养殖饲料和新型药物最有前途的资源之一。其中，四鞭藻属的绿藻因其在营养饥饿条件下积累脂质而被广泛研究。在本文中，我们展示了四鞭藻的完整转录组，并对氮饥饿和氮充足（在静止期）条件下的差异表达进行了分析，不仅关注脂质代谢，还对营养饥饿反应提供了新的见解。当四鞭藻在氮饥饿条件下培养时，涉及信号转导途径、应激和抗氧化反应以及溶质运输的转录本被强烈上调。相反，在相同条件下，参与氨基酸合成、糖降解、次生代谢物合成以及光合作用活性的转录本被下调。在差异表达的转录本中，鉴定出一种聚酮合酶和三种脂氧合酶（参与具有抗捕食、抗癌和抗感染活性的次生代谢物的合成），表明该微藻可能合成生物活性化合物。此外，本文首次报道了一种假定的腈酶（用于腈生物修复的酶）的转录本用于四鞭藻。这些发现为四鞭藻对营养饥饿的反应以及绿藻的可能生物技术应用提供了新的见解。
