Metabolic engineering Camelina sativa with fish oil-like levels of DHA.
BACKGROUND
Omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are critical for human health and development [corrected].. Numerous studies have indicated that deficiencies in these fatty acids can increase the risk or severity of cardiovascular, inflammatory and other diseases or disorders. EPA and DHA are predominantly sourced from marine fish although the primary producers are microalgae. Much work has been done to engineer a sustainable land-based source of EPA and DHA to reduce pressure on fish stocks in meeting future demand, with previous studies describing the production of fish oil-like levels of DHA in the model plant species, Arabidopsis thaliana.


RESULTS
In this study we describe the production of fish oil-like levels (>12%) of DHA in the oilseed crop species Camelina sativa achieving a high ω3/ω6 ratio. The construct previously transformed in Arabidopsis as well as two modified construct versions designed to increase DHA production were used. DHA was found to be stable to at least the T5 generation and the EPA and DHA were found to be predominantly at the sn-1,3 positions of triacylglycerols. Transgenic and parental lines did not have different germination or seedling establishment rates.


CONCLUSIONS
DHA can be produced at fish oil-like levels in industrially-relevant oilseed crop species using multi-gene construct designs which are stable over multiple generations. This study has implications for the future of sustainable EPA and DHA production from land-based sources.
CSIRO Food Futures National Research Flagship, Canberra, Australian Capital Territory, Australia.
James R
JR
Petrie
CSIRO Food Futures National Research Flagship, Canberra, Australian Capital Territory, Australia.
Pushkar
P
Shrestha
CSIRO Food Futures National Research Flagship, Canberra, Australian Capital Territory, Australia.
Srinivas
S
Belide
CSIRO Food Futures National Research Flagship, Canberra, Australian Capital Territory, Australia.
Yoko
Y
Kennedy
CSIRO Food Futures National Research Flagship, Canberra, Australian Capital Territory, Australia.
Geraldine
G
Lester
CSIRO Food Futures National Research Flagship, Canberra, Australian Capital Territory, Australia.
Qing
Q
Liu
CSIRO Food Futures National Research Flagship, Canberra, Australian Capital Territory, Australia.
Uday K
UK
Divi
CSIRO Materials Science and Engineering, Clayton, Victoria, Australia.
Roger J
RJ
Mulder
CSIRO Food Futures National Research Flagship, Hobart, Tasmania, Australia.
Maged P
MP
Mansour
CSIRO Food Futures National Research Flagship, Hobart, Tasmania, Australia.
Peter D
PD
Nichols
CSIRO Food Futures National Research Flagship, Canberra, Australian Capital Territory, Australia.
Surinder P
SP
Singh
D016960:Agrobacterium tumefaciens / Q000235:genetics; D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D019607:Brassicaceae / Q000235:genetics / Q000378:metabolism*; D015118:Eicosapentaenoic Acid / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D005399:Fishes; D018506:Gene Expression Regulation, Plant; D005822:Genetic Vectors; D018525:Germination / Q000502:physiology; D060847:Metabolic Engineering; D030821:Plants, Genetically Modified / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D036226:Seedlings / Q000502:physiology
D005231:Fatty Acids, Unsaturated; D015118:Eicosapentaenoic Acid; C026219:docosapentaenoic acid