Effects of drought on [1-14C]-oleic and [1-14C]-linoleic acid desaturation in cotton leaves |
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Authors: | A. T. Pham Thi,C. Borrel-Flood,J. Vieí ra da Silva,A. M. Justin,P. Mazliak |
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Affiliation: | Lab. d'Ecologie générale et appliquée, Univ. de Paris VII, 2 Place Jussieu, F-75221 Paris Cedex 05, France;Lab. de Physiologie Cellulaire, Univ. Pierre et Marie Curie, 4 Place Jussieu, F-75230 Paris Cedex 05, France. |
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Abstract: | The effects of water stress on [1-14C]-oleic and [1-14C]-linoleic acid desaturations were studied in leaves of two varieties of cotton ( Gossypium hirsutum L.), one drought-sensitive (Reba) and the other more resistant (Mocosinho). After 24 h incorporation, [1-14C]-oleate led to the appearance of linoleate in phospholipids and, additionally, of linolenate in galactolipids. [1-14C]-Linoleate was desaturated to linolenate only in galactolipid fractions. Water stress markedly inhibited the incorporation of the precursors into the leaf lipids. The two desaturation steps were affected, particularly the transformation of linoleate to linolenate in monogalactosyldiacylglycerol in the drought-sensitive variety of cotton. The metabolic implications of the inhibition of the biosynthesis of C18-polyunsaturated fatty acids are discussed. |
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Keywords: | Fatty acids Gossypium hirsutum lipids |
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