Accessible Requires Authentication Published by De Gruyter September 29, 2014

Transcriptome sequencing of the marine microalga, Chlorella pyrenoidosa (Chlorophyta), and analysis of carbonic anhydrase expression under salt stress

Xue Sun, Weiwei Wang, Jia Shen and Nianjun Xu
From the journal Botanica Marina


In this study, the transcriptome of the marine microalga, Chlorella pyrenoidosa 820, was sequenced by high-throughput RNA-seq using Illumina HiSeq 2000. Because the genome sequence of this species is unknown, the resulting transcriptome was assembled de novo and annotated. This resulted in 4.71G clean nucleotides with a 56.91% GC content and yielded a total of 36,826 unigenes with a mean length of 1089 nt. Among these, 23,015 unigenes were annotated in the NCBI-NR, NCBI-NT, Swiss-Prot, KEGG, COG, and GO databases with a cutoff E-value of 10-5. In the annotated sequences, 21 unigenes were identified as carbonic anhydrase (CA), which is an important enzyme in the CO2-concentrating mechanism (CCM), and were homologous to nine α-, eight β-, and four γ-CAs. Interestingly, the expression of three CA subtypes, including one α-, one β-, and one γ-CA, analyzed by real-time quantitative PCR, showed induction by high salinity. These results will enrich the CA gene information in the database and will help understand CCM in the genus Chlorella.

Corresponding author: Nianjun Xu, Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Zhejiang Ningbo 315211, P.R. China, e-mail:


This work was funded by the National Natural Science Foundation of China (30700610), Natural Science Foundation of Zhejiang Province (LY13D060007), and the Project of Science and Technology Innovation Team of Zhejiang Province (2010R50025-25). This research was also sponsored by the K.C. Wong Magna Fund from the Ningbo University.


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Received: 2014-3-11
Accepted: 2014-9-2
Published Online: 2014-9-29
Published in Print: 2014-10-1

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