Nitrogen is a critical macronutrient for plant growth and development, and Dunaliella salina has various physiological responses to nitrogen deprivation, such as accumulating large amounts of carotenoids in its chloroplasts. However, little is known about the underlying global molecular response of D. salina to nitrogen deprivation. Herein, we used the Illumina platform to interrogate which genes of D. salina respond to nitrogen deprivation. The RNA-seq libraries of D. salina TG cultured under nitrogen-replete and -depleted conditions for 7 days generated 87,160,704 valid reads with an average length of 124.94 bp. De novo assembly produced 73,329 transcripts with an average length of 801 bp and 47,283 unigenes with an average length of 675 bp. 5803 unigenes were assigned to 50 gene ontology (GO) terms belonging to three main categories. A total of 6016 unigenes with 671 enzyme commission numbers were assigned to 251 predicted KEGG metabolic pathways, and 6296 unigenes were categorized into 25 KOG classifications. A total of 27,306 CDS were predicted from the 47,283 unigenes. Analysis of transcription levels revealed that 2380 genes were upregulated and 747 were downregulated during nitrogen deprivation. These nitrogen-deprivation responsive genes and differentially expressed transcriptional regulator genes were identified by GO classification. The transcriptome data may serve as a reference for further analysis of gene expression and functional genomics studies, and will facilitate the study of carotenoid biosynthesis and nitrogen metabolism in chlorophytes at the molecular level.

中文翻译：

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杜氏盐藻TG菌株氮剥夺反应基因的RNA-Seq和转录组分析

氮是植物生长和发育的重要常量营养素，杜氏盐藻对氮缺乏具有多种生理反应，例如在其叶绿体中积累大量类胡萝卜素。但是，关于盐藻对氮剥夺的潜在整体分子反应知之甚少。在这里，我们使用Illumina平台来询问盐藻D. salina的哪些基因对氮剥夺作出反应。盐藻D. salina的RNA-seq文库在富氮和贫氮条件下培养7天的TG产生87,160,704个有效读数，平均长度为124.94 bp。从头组装产生了73,329个转录本，平均长度为801 bp，以及47,283个单基因，平均长度为675 bp。5803个单基因被分配给属于三个主要类别的50个基因本体（GO）术语。共有6016个单基因与671个酶的佣金编号分配给251条预测的KEGG代谢途径，并且将6296个单基因分类为25个KOG分类。从47,283个单基因中预测总共有27,306个CDS。转录水平的分析表明，在氮剥夺期间，2380个基因被上调，而747个基因被下调。通过GO分类鉴定了这些氮缺乏响应基因和差异表达的转录调节基因。转录组数据可作为进一步分析基因表达和功能基因组学研究的参考，并将有助于在分子水平上研究叶绿素中类胡萝卜素的生物合成和氮代谢。