Background
The regulation of genes related to lipid metabolism by genetic engineering is an important way to increase the accumulation of lipids in microalgae. DNA binding with one finger (DOF) is a plant-specific transcription factor in higher plants, where it regulates carbon and nitrogen metabolic pathways by regulating key genes involved in these pathways. Overexpression of DOF can increase lipid production in plants; however, it is not clear whether overexpression of DOF can increase lipids in microalgae.
Results
In this study, we cloned a DOF transcription factor, crDOF, from
Chlamydomonas reinhardtii
. The sequence of this transcription factor is 1875 bp and encodes a peptide of 624 amino acids with a conserved DOF domain. Overexpression of crDOF in
C. reinhardtii
significantly increased the intracellular lipid content. The content of total fatty acids in the transgenic algae line Tran
c-crDOF
-12 was 126.01 μg/mg (dry weight), which was 23.24% higher than that of the wild type. Additionally, the content of unsaturated fatty acids in the transgenic Tran
c-crDOF
-12 line increased significantly. Fluorescence quantitative PCR analysis showed that in the transgenic line Tran
c-crDOF
-12, the expression levels of BCC1, FAT1, SQD1, MGD1, DGD1 and PGP1 genes were significantly upregulated, while the expression levels of ACP1, ACS1, CIS1 and SQD2 were downregulated.
Conclusions
Our results confirm that crDOF increases intracellular lipids in
C. reinhardtii
by regulating key genes involved in lipid metabolism. According to these findings, we propose that enhancing the lipid content in microalgae by overexpressing DOF may be achieved in other industrial strains of microalgae and be employed for the industrial production of biodiesel.
Electronic supplementary material
The online version of this article (10.1186/s13068-019-1403-1) contains supplementary material, which is available to authorized users.
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