In vitro: |
Plant ence, 1989, 64(2):167-177. | The effects of different cultural conditions on the accumulation of depot lipids notably petroselinic acid during somatic embryogenesis in Daucus carota L.[Reference: WebLink] | METHODS AND RESULTS:
Total lipid content and the fatty acid composition of total lipids (TL), of triacylglycerols (TAG), and of total poplar lipids (PL) were investigated in tissue culture and somatic embryoids of Daucus carota L. Total lipids were approx. 0.2% of fresh weight in callus and suspension culture but approx. 0.5% in heart and torpedo shaped embryoids. Petroselinic acid (), which is approx. 70% of carrot seed oil, was not present in callus, suspension culture (0 time) and globular embryoids. The appearance of this fatty acid started in the heart shaped embryoids and reached a maximum level of 1.4% in the TAG of torpedo shaped embryoids. The major fatty acids invariably in all kinds of tissues where linoleic (18:2) and palmitic (16:0) acids, and the minor ones were stearic (18:0), oleic (), vaccenic () and linolenic (18:3) acid. Different cultural conditions could not boost petroselinic acid accumulation but did increase TAG content in total lipids and total lipids in embryoids with a maximum level of approx. 17 mg TAG per g fresh weight. Abscisic acid, sorbitol and these in combination gave the maximum level of total lipids per g fresh weight; approx. 75% of the lipids were TAG.
CONCLUSIONS:
The results from this study, showing low levels of petroselinic acid in later stages embryoids but not in undifferentiated tissues point to weak but distinct embryo specific expression of gene(s) governing the biosynthesis of petroselinic acid. |
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