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Lipidomic analysis of Arabidopsis seed genetically engineered to contain DHA.

Zhou XR, Callahan DL, Shrestha P, Liu Q, Petrie JR, Singh SP - Front Plant Sci (2014)

Bottom Line: Metabolic engineering of omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA) in oilseeds has been one of the key targets in recent years.Liquid chromatography-mass spectrometry (LC-MS) was used to characterize the triacylglycerol (TAG), diacylglycerol (DAG) and phospholipid (PL) lipid classes in the transgenic and wild type Arabidopsis seeds at both developing and mature stages.Trace amounts of di-DHA PC and tri-DHA TAG were identified and confirmed by high resolution MS/MS.

View Article: PubMed Central - PubMed

Affiliation: Food Futures National Research Flagship, Commonwealth Scientific and Industrial Research Organisation Canberra, ACT, Australia ; Plant Industry, Commonwealth Scientific and Industrial Research Organisation Canberra, ACT, Australia.

ABSTRACT
Metabolic engineering of omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA) in oilseeds has been one of the key targets in recent years. By expressing a transgenic pathway for enhancing the synthesis of the ω3 LC-PUFA docosahexaenoic acid (DHA) from endogenous α-linolenic acid (ALA), we obtained the production of fish oil-like proportions of DHA in Arabidopsis seed oil. Liquid chromatography-mass spectrometry (LC-MS) was used to characterize the triacylglycerol (TAG), diacylglycerol (DAG) and phospholipid (PL) lipid classes in the transgenic and wild type Arabidopsis seeds at both developing and mature stages. The analysis identified the appearance of several abundant DHA-containing phosphatidylcholine (PC), DAG and TAG molecular species in mature seeds. The relative abundances of PL, DAG, and TAG species showed a preferred combination of LC-PUFA with ALA in the transgenic seeds, where LC-PUFA were esterified in positions usually occupied by 20:1ω9. Trace amounts of di-DHA PC and tri-DHA TAG were identified and confirmed by high resolution MS/MS. Studying the lipidome in transgenic seeds provided insights into where DHA accumulated and combined with other fatty acids of neutral and phospholipids from the developing and mature seeds.

No MeSH data available.


Phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylglycerol (PG) pools in the developing and the mature Arabidopsis seeds. The phospholipids PE (A), PG (B) and PI (C) species are annotated similarly to PC. Data are shown as the mean of triplicate analysis with the error bars representing the standard deviations.
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Figure 5: Phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylglycerol (PG) pools in the developing and the mature Arabidopsis seeds. The phospholipids PE (A), PG (B) and PI (C) species are annotated similarly to PC. Data are shown as the mean of triplicate analysis with the error bars representing the standard deviations.

Mentions: LC-PUFA in other PL groups were also analyzed (Figure 5). PE was the second largest pool of PL. However, only low levels of LC-PUFA appeared in the PE pool. LC-PUFA was much lower in the PI and PG pools. Interestingly, the most significant increase in these three pools of PL in GA7 was 34:3 (possibly composed of palmitic acid and ALA) when compared to the WT. Another interesting aspect was that the much lower levels of PG was found in the GA7 developing seeds, compared to PE and PI. The PS pool was very small, and the LC-MS responses to most of the PS species were close to the detection limit (see Figure S2).


Lipidomic analysis of Arabidopsis seed genetically engineered to contain DHA.

Zhou XR, Callahan DL, Shrestha P, Liu Q, Petrie JR, Singh SP - Front Plant Sci (2014)

Phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylglycerol (PG) pools in the developing and the mature Arabidopsis seeds. The phospholipids PE (A), PG (B) and PI (C) species are annotated similarly to PC. Data are shown as the mean of triplicate analysis with the error bars representing the standard deviations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150447&req=5

Figure 5: Phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylglycerol (PG) pools in the developing and the mature Arabidopsis seeds. The phospholipids PE (A), PG (B) and PI (C) species are annotated similarly to PC. Data are shown as the mean of triplicate analysis with the error bars representing the standard deviations.
Mentions: LC-PUFA in other PL groups were also analyzed (Figure 5). PE was the second largest pool of PL. However, only low levels of LC-PUFA appeared in the PE pool. LC-PUFA was much lower in the PI and PG pools. Interestingly, the most significant increase in these three pools of PL in GA7 was 34:3 (possibly composed of palmitic acid and ALA) when compared to the WT. Another interesting aspect was that the much lower levels of PG was found in the GA7 developing seeds, compared to PE and PI. The PS pool was very small, and the LC-MS responses to most of the PS species were close to the detection limit (see Figure S2).

Bottom Line: Metabolic engineering of omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA) in oilseeds has been one of the key targets in recent years.Liquid chromatography-mass spectrometry (LC-MS) was used to characterize the triacylglycerol (TAG), diacylglycerol (DAG) and phospholipid (PL) lipid classes in the transgenic and wild type Arabidopsis seeds at both developing and mature stages.Trace amounts of di-DHA PC and tri-DHA TAG were identified and confirmed by high resolution MS/MS.

View Article: PubMed Central - PubMed

Affiliation: Food Futures National Research Flagship, Commonwealth Scientific and Industrial Research Organisation Canberra, ACT, Australia ; Plant Industry, Commonwealth Scientific and Industrial Research Organisation Canberra, ACT, Australia.

ABSTRACT
Metabolic engineering of omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA) in oilseeds has been one of the key targets in recent years. By expressing a transgenic pathway for enhancing the synthesis of the ω3 LC-PUFA docosahexaenoic acid (DHA) from endogenous α-linolenic acid (ALA), we obtained the production of fish oil-like proportions of DHA in Arabidopsis seed oil. Liquid chromatography-mass spectrometry (LC-MS) was used to characterize the triacylglycerol (TAG), diacylglycerol (DAG) and phospholipid (PL) lipid classes in the transgenic and wild type Arabidopsis seeds at both developing and mature stages. The analysis identified the appearance of several abundant DHA-containing phosphatidylcholine (PC), DAG and TAG molecular species in mature seeds. The relative abundances of PL, DAG, and TAG species showed a preferred combination of LC-PUFA with ALA in the transgenic seeds, where LC-PUFA were esterified in positions usually occupied by 20:1ω9. Trace amounts of di-DHA PC and tri-DHA TAG were identified and confirmed by high resolution MS/MS. Studying the lipidome in transgenic seeds provided insights into where DHA accumulated and combined with other fatty acids of neutral and phospholipids from the developing and mature seeds.

No MeSH data available.