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Comparison of Fatty Acid Metabolism of Two Oleic and One Conventional Sunflower Hybrids: A New Hypothesis
Author(s) -
Lagravère T.,
Kleiber D.,
Surel O.,
Calmon A.,
Bervillé A.,
Dayde J.
Publication year - 2004
Publication title -
journal of agronomy and crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.095
H-Index - 74
eISSN - 1439-037X
pISSN - 0931-2250
DOI - 10.1111/j.1439-037x.2004.00099.x
Subject(s) - achene , oleic acid , helianthus annuus , sunflower , hybrid , linoleic acid , biology , biochemistry , food science , fatty acid , botany , horticulture
Studies on oleic sunflower ( Helianthus annuus L.) were carried out in order to determine which mechanism produces oleic and linoleic acids in oleic hybrids. The fatty acid composition of different lipid fractions (structural and storage forms) was followed during the achene development of three hybrids including cv. Santiago (non‐oleic hybrid), cv. Olbaril and cv. Trisun 870 (high oleic hybrids). In addition, a simple physiological model of fatty acid accumulation was developed. In order to complete this biochemical approach, a molecular study of desaturase gene accumulation has been preformed. The evolution of oleic and linoleic acid contents in achenes revealed the lack of Δ12‐desaturase activity in oleic hybrids and also indicated differences between oleic genotypes related to linoleic acid content in the first days after pollination and until maturity. Molecular studies (using Northern blot analysis) confirmed that the Δ12‐desaturase transcript was not expressed at the same time in oleic hybrids. These observations were confirmed by studies on the selective dispatching of oleic and linoleic acids in different lipid fractions during achene development. Trisun 870 showed a very low content of linoleic acid in triglycerides throughout achene maturation, whereas Olbaril presented a higher initial content followed by a rapid decrease. These results led us to put forward a new hypothesis for fatty acid biosynthesis in the oleic sunflower hybrids.