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Functional characterization of microsomal fatty acid desaturation pathway genes in Buglossoides arvensis : A stearidonic acid rich oilseed plant
Author(s) -
Prasad P,
Sreedhar RV
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.486.7
Subject(s) - linoleic acid , fatty acid desaturase , biochemistry , fatty acid , polyunsaturated fatty acid , oleic acid , biology , linolenic acid , metabolic engineering , enzyme , chemistry , food science
Buglossoides arvensis seed oil contains a significant amount of stearidonic acid (SDA, 18:4 n−3), an unusual omega‐3‐fatty acid with nutraceutical potential superior to α‐linoleic acid (18:3 n−3). Stearidonic acid biosynthesis occurs by sequential desaturation of oleic acid, linoleic acid and α‐linolenic acid by Delta‐12‐desaturase (FAD2), Delta‐15‐desaturase (FAD3) and Delta‐6‐desaturase (D6D), respectively. Molecular characterization of these enzymes was essential to exploit them as potential target genes for transgenic production of SDA in traditional oilseed crops. In the present study, putative full‐length coding sequence of Ba FAD2, Ba FAD3 and Ba D6D genes were identified from B. arvensis developing seed transcriptome data (NCBI SRA ID: SRX2191688). Absolute quantification of gene expression levels by quantitative RT‐PCR showed that Ba FAD2, Ba FAD3 and Ba D6D genes were ubiquitously expressed in both vegetative and reproductive tissues but with different levels of transcript abundance. Ba FAD2, Ba FAD3 and Ba D6D were cloned in yeast expression vector pYES/NTC and were functionally characterized by heterologous expression in Saccharomyces cerevisiae strain INVSC1 . Overexpression followed fatty acid feeding studies in INVSC1 strain revealed that the encoded enzyme activities of Ba FAD2 and Ba FAD3 efficiently converted oleic acid and linoleic acid into linoleic acid and α‐linolenic acid, respectively. Ba D6D efficiently converted both linolenic and α‐linolenic acid substrates in to γ‐linolenic acid and stearidonic acid, respectively. In conclusion, the identification and characterization of these new fatty acid desaturase genes not only provide an insight into the biosynthesis of SDA in B. arvensis but also expand the repository of fatty acid desaturase targets available for genetic engineering of omega‐3 fatty acid traits in traditional oilseed crops. Support or Funding Information This research is financially supported by the Council of Scientific and Industrial Research (CSIR), New Delhi, under the 12th five‐year plan project LIPIC (BSC0401). Prasad P is grateful to UGC, New Delhi, India for providing senior research fellowship and United States‐India Educational Foundation, India for providing Fulbright Fellowship. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .