Biotechnology Bulletin ›› 2015, Vol. 31 ›› Issue (7): 101-108.doi: 10.13560/j.cnki.biotech.bull.1985.2015.07.015

• Research report • Previous Articles     Next Articles

Bioinformatics Analysis and Expression Study of DHDDS of Dunaliella viridis

Pan Yifang, Gong Yifu, Yu Kai, Zhu Shuaiqi, Wang Heyu   

  1. (School of Marine Science,Ningbo University,Ningbo 315211)
  • Received:2014-12-02 Online:2015-07-16 Published:2015-07-16

Abstract: Dunaliella viridis is a unicellular green alga producing valuable secondary metabolite carotenoids, and dehydrodolichyl diphosphate synthase(DHDDS)is an enzyme in the synthesis pathway of carotenoids. It was to investigate the correlation between expression of DHDDS gene in D. viridis treated with different concentrations of MeJA and the content of carotenoids. Total RNA was extracted from D. viridis and the full length of DHDDS was acquired by de-novo transcriptome sequencing, then the sequence was analyzed by bioinformatics website and software to predict the protein structure. Transcriptional levels of D. viridis treated with different concentrations of MeJA were examined by Real-time quantitative PCR(RT-qPCR). The total length of gene DHDDS was 2 211 bp, containing a 1 740 bp open reading frame(ORF)that encoded 579 amino acids. Theoretical isoelectric point of DHDDS protein was 7.63. Relative molecular mass was 62 472.7 Da. Bioinformatics prediction revealed that there was no signal peptide and transmembrane domain in DHDDS protein, and it was located in cytoplasmic matrix. Sequence alignment showed that DHDDS of D. viridis shared the highest homology of 59% with that of Chlorella variabilis. The RT-qPCR showed that the expression of DHDDS gene in D. viridis treated by 100 mol/L of MeJA was the highest with significant difference:at this concentration, the content of carotenoids was higher than other groups. There was certain correlation between the expression of DHDDS gene and the content of carotenoids. Conclusively, the DHDDS of D. viridis is an enzyme located in cytoplasmic matrix, relating to synthesis pathway of carotenoids. Within certain concentration, MeJA in lower concentration shows promoting effect on the expression, and inhibiting in higher concentration, there is a correlation between the expression and the content of carotenoids.

Key words: Dunaliella viridis, DHDDS, carotenoids contents, MeJA