Abstract
Phaeodactylum tricornutum is a diatom that is rich in lipids. Recently, it has received much attention as a feedstock for biodiesel production. Nitrogen deficiency is widely known to increase the content of neutral lipids (mainly triacylglycerides, or TAGs) of microalgae, including P. tricornutum, but the mechanism is unclear. In this study, we deciphered the correlations between TAG content and nine key enzymatic genes involved in lipid synthesis in P. tricornutum. After being cultured under nitrogen-free conditions for 0, 4, 24, 48, 72, 120, and 168 h, the TAG contents of P. tricornutum cells were assayed and the transcript abundances of the target genes were monitored by quantitative real-time PCR. The results show that the abundances of four target gene transcripts (LACS3, G3PDH2, G3PDH3, and G3PDH5) were positively correlated with TAG content, indicating that these genes may be involved in TAG synthesis in P. tricornutum. The findings improve our understanding of the metabolic network and regulation of lipid synthesis and will guide the future genetic improvement of the TAG content of P. tricornutum.
Similar content being viewed by others
References
Ahmad A L, Mat Yasin N H, Derek C J C, Lim J K. 2011. Microalgae as a sustainable energy source for biodiesel production: A review. Renew. Sust. Energ. Rev., 15: 584–593.
Apt K E, Kroth-Pancic P G, Grossman A R. 1996. Stable nuclear transformation of the diatom Phaeodactylum tricornutum. Mol. Gen. Genet., 252(5): 572–579.
Armbrust E V. 2009. The life of diatoms in the world’s oceans. Nature, 459: 185–192.
Black P N, DiRusso C C. 2007. Yeast acyl-CoA synthetases at the crossroads of fatty acid metabolism and regulation. Biochimica et Biophysica Acta (BBA) -Molecular and Cell Biology of Lipids, 1771: 286–298.
Chen W, Zhang C, Song L, Sommerfeld M, Hu Q. 2009. A high throughput Nile red method for quantitative measurement of neutral lipids in microalgae. J. Microbiol. Meth., 77: 41–47.
Chomczynski P, Sacchi N. 1987. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenolchloroform extraction. Anal. Biochem., 162(1): 156–159.
Dheda K, Hugett J F, Chang J S, Kim L U, Bustin S A, Johnson M A, Rook G A W, Zumla A. 2005. The implications of using an inappropriate reference gene for real-time reverse transcription PCR data normalization. Anal. Biochem., 344: 141–143.
Digel M, Ehehalt R, Stremmel W, Füllekrug J. 2009. Acyl-CoA synthetases: fatty acid uptake and metabolic channeling. Mol. Cell. Biochem., 326: 23–28.
Dunahay T G, Jarvis E E, Roessler P G. 1995. Genetic transformation of the diatoms Cyclotella cryptica and Navicula saprophila. J. Phycol., 31(6): 1 004–1 012.
Ellis J M, Frahm J L, Li L O, Coleman R A. 2010. Acylcoenzyme A synthetases in metabolic control. Curr. Opin. Lipidol., 21: 212–217.
Fulda M, Schnurr J, Abbadi A, Heinz E, Browse J. 2004. Peroxisomal acyl-CoA synthetase activity is essential for seedling development in Arabidopsis thaliana. Plant Cell, 16: 394–405.
Germain V, Rylott E L, Larson T R, Sherson S M, Bechtold N, Carde J P, Bryce J H, Graham I A, Smith S M. 2001. Requirement for 3-ketoacyl-CoA thiolase-2 in peroxisome development, fatty acid β-oxidation and breakdown of triacylglycerol in lipid bodies of Arabidopsis seedlings. Plant. J., 28(1): 1–12.
Guerrini F, Cangini M, Boni L, Trost P, Pistocchi R. 2000. Metabolic responses of the diatom Achnanthes brevipes (Bacillariophyceae) to nutrient limitation. J. Phycol., 36: 882–890.
Guillard R R L, Ryther J H. 1962. Studies of marine planktonic diatoms: Cyclotella nana Hustedt, and Detonula confervacea (Cleve) Gran. Can. J. Microbiol., 8: 229–239.
Illman A M, Scragg A H, Shales S W. 2000. Increase in Chlorella strains calorific values when grown in low nitrogen medium. Enzyme. Microb. Tech., 27: 631–635.
Klaus D, Ohlrogge J B, Neuhaus H E, Dörmann P. 2004. Increased fatty acid production in potato by engineering of acetyl-CoA carboxylase. Planta, 219: 389–396.
Lee P D, Sladek R, Greenwood C M, Hudson T J. 2002. Control genes and variability: absence of ubiquitous reference transcripts in diverse mammalian expression studies. Genome. Res., 12: 292–297.
Li Y, Horsman M, Wang B, Wu N, Lan C Q. 2008. Effects of nitrogen sources on cell growth and lipid accumulation of green alga Neochloris oleoabundans. Appl. Microbiol. Biotechnol., 81: 629–636.
Livak K J, Schmittgen T D. 2001. Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method. Methods, 25: 402–408.
Pfaffl M W. 2001. A new mathematical model for relative quantification in real-time RT-PCR. Nucleic. Acids. Res., 29(9): e45.
Ramachandra T V, Mahapatra D M, Karthick B, Gordon R. 2009. Milking diatoms for sustainable energy: biochemical engineering versus gasoline-secreting diatom solar panels. Ind. Eng. Chem. Res., 48(19): 8 769–8 788.
Renaud S M, Parry D L, Thinh L V, Kuo C, Padovan A, Sammy N. 1991. Effect of light intensity on the proximate biochemical and fatty acid composition of Isochrysis sp. and Nannochloropsis oculata for use in tropical aquaculture. J. Appl. Phycol., 3: 43–53.
Riso D V, Raniello R, Maumus F, Rogato A, Bowler C, Falciatore A. 2009. Gene silencing in the marine diatom Phaeodactylum tricornutum. Nucleic. Acids. Res., 37(14): e96.
Roesler K, Shintani D, Savage L, Boddupalli S, Ohlrogge J. 1997. Targeting of the Arabidopsis homomeric acetylcoenzyme A carboxylase to plastids of rapeseeds. Plant. Physiol., 113: 75–81.
Siaut M, Heijde M, Mangogna M, Montsant A, Coesel S, Allen A, Manfredonia A, Falciatore A, Bowler C. 2007. Molecular toolbox for studying diatom biology in Phaeodactylum tricornutum. Gene, 406: 23–35.
Tricarico C, Pinzani P, Bianchi S, Paglierani M, Distante V, Pazzagli M, Bustin S A, Orlando C. 2002. Quantitative real-time reverse transcription polymerase chain reaction: normalization to rRNA or single housekeeping genes is inappropriate for human tissue biopsies. Anal. Biochem., 309: 293–300.
Vigeolas H, Waldeck P, Zank T, Geigenberger P. 2007. Increasing seed oil content in oil-seed rape (Brassica napus L.) by over-expression of a yeast glycerol-3-phosphate dehydrogenase under the control of a seedspecific promoter. Plant. Biotechnol. J., 5: 431–441.
Wei Y D, Periappuram C, Datla R, Selvaraj G, Zou J T. 2001. Molecular and biochemical characterizations of a plastidic glycerol-3-phosphate dehydrogenase from Arabidopsis. Plant. Physiol. Bioch., 39: 841–848.
Zaslavskaia L A, Lippmeier J C, Kroth P G, Grossman A R, Apt K E. 2000. Transformation of the diatom Phaeodactylum tricornutum (Bacillariophyceae) with a variety of selectable marker and reporter genes. J. Phycol., 36: 379–386.
Author information
Authors and Affiliations
Corresponding author
Additional information
Supported by the National Basic Research Program of China (973 Program) (No. 2011CB200901), the National Key Technology Research and Development Program (No. 2011BAD14B01), the Promotive Research Fund for Excellent Young and Middle-Aged Scientists of Shandong Province (No. BS2010SW037), and the National Natural Science Foundation of China (No. 31270408)
Rights and permissions
About this article
Cite this article
Zhang, L., Han, J., Yang, G. et al. Association of triacylglyceride content and transcript abundance of genes involving in lipid synthesis of nitrogen deficient Phaeodactylum tricornutum . Chin. J. Ocean. Limnol. 32, 397–402 (2014). https://doi.org/10.1007/s00343-014-3173-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00343-014-3173-8