Algal Research ( IF 5.1 ) Pub Date : 2020-12-22 , DOI: 10.1016/j.algal.2020.102147 Hexin Lv , Minjae Kim , Seunghye Park , Kwangryul Baek , Hyeonjun Oh , Juergen E.W. Polle , EonSeon Jin
Dunaliella salina is a model photosynthetic organism for studying osmoregulation. To further understand the molecular basis of short-term hyperosmotic-stress responses, gene expression was investigated by RNA-Seq of D. salina cells sampled at 15, 30, 60, and 120 min following exposure to salt and glycerol stress. De novo reconstruction of the transcriptome using Illumina paired-end reads generated 155,996 contigs, out of which 31,302 transcripts could be annotated by gene ontology, assigning them to 64 functional groups. Further functional analysis of the transcripts was performed using KEGG Enzyme Commission numbers. Out of a total of 4415 transcripts with more than two-fold differential expression, 479 transcripts were identified representing 414 enzyme commission numbers that were mapped to 120 KEGG pathways. The “Chromosome and associated proteins”, “Transporters”, “Cytoskeleton proteins”, and 92 other KEGG pathways mapped for differentially expressed transcripts were common to salt stress and glycerol stress. In addition, differentially expressed transcripts mapped uniquely to 22 metabolic pathways for glycerol stress and 7 metabolic pathways mapped uniquely for salt stress. The transcripts mapping to core carbon metabolism within starch, glycolysis, Calvin cycle, and glycerol metabolic pathways were analyzed and 19 transcripts showed differential expression. Cluster analysis resulted in the identification of 939 transcripts, which showed similar expression trends. Among the fastest and most strongly induced genes, glyoxylate cycle and fatty acid desaturation-related genes implied the induction of photorespiration following rapid shifts in the osmolarity of the growth medium. These results provide novel insights for further analyses of physiological responses to short-term osmotic shock.
中文翻译:
绿藻杜氏盐藻对盐和甘油高渗胁迫的短期响应的比较转录组分析
杜氏盐藻(Dunaliella salina)是用于研究渗透调节的模型光合生物。为了进一步了解短期高渗应激反应的分子基础,通过盐藻的RNA-Seq研究了基因表达在暴露于盐和甘油胁迫下第15、30、60和120分钟对细胞进行采样。使用Illumina的双末端读取从头开始重新构建转录组,生成了155,996个contig,其中31,302个转录本可以通过基因本体注释,将它们分配给64个功能组。使用KEGG酶委员会编号对转录物进行进一步的功能分析。在具有超过两倍的差异表达的总共4415个转录物中,鉴定出479个转录物,代表414个酶的佣金编号,它们映射到120个KEGG途径。映射到差异表达的转录本的“染色体和相关蛋白”,“转运蛋白”,“骨架蛋白”和其他92条KEGG途径在盐胁迫和甘油胁迫中很常见。此外,差异表达的转录本独特地映射到甘油应激的22个代谢途径和7种独特地针对盐胁迫的代谢途径。分析了映射到淀粉,糖酵解,卡尔文循环和甘油代谢途径中核心碳代谢的转录本,并且有19个转录本显示差异表达。聚类分析确定了939个转录本,显示出相似的表达趋势。在最快和最强烈诱导的基因中,乙醛酸循环和脂肪酸去饱和相关基因暗示在生长培养基的渗透压快速变化后诱导光呼吸。这些结果为进一步分析对短期渗透压休克的生理反应提供了新的见解。