Biochemical characterization of a high-palmitoleic acid Helianthus annuus mutant.
In the present work we carried out analytical and biochemical studies on a new high-n-7 monounsaturated fatty acid sunflower (Helianthus annuus L.) mutant. This new line, which has been selected by classical methods of breeding and mutagenesis, shows contents of unusual acyl chains up to 20% (12% of 16:1DELTA9, 5% of 16:2delta9,12 and 6% of 18:1delta11), whereas those fatty acids are found in negligible amounts in common sunflower cultivars. This characterization involved in vivo incubations with radiolabeled acetate and measurement of the last enzymes involved in the intraplastidial de novo fatty acid synthesis: beta-ketoacyl-ACP synthase II, stearoyl-ACP desaturase (EC 1.14.19.2) and acyl-ACP thioesterases (EC 3.1.2.14). Results indicated that the high-palmitoleic acid phenotype was associated with a concerted reduction in the fatty acid synthase II activity with respect to the control lines and an increase of stearoyl-ACP desaturase activity with respect to the high-palmitate mutant line.
Salas
Joaquín J
JJ
Dep. Fisiología y Tecnología de Productos Vegetales, Instituto de la Grasa, Av. Padre García Tejero, 4, 41012 Sevilla, Spain.
Martínez-Force
Enrique
E
Garcés
Rafael
R
D000085:Acetates / Q000737:chemistry; D000123:Acetyltransferases / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D002855:Chromatography, Thin Layer; D044943:Fatty Acid Desaturases / Q000378:metabolism; D054889:Fatty Acid Synthase, Type II; D005227:Fatty Acids / Q000378:metabolism; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism*; D006368:Helianthus / Q000235:genetics*; D009097:Multienzyme Complexes / Q000378:metabolism; D016296:Mutagenesis; D009154:Mutation; D019308:Palmitic Acid / Q000378:metabolism; D013869:Thiolester Hydrolases / Q000378:metabolism
D000085:Acetates; D029681:Arabidopsis Proteins; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D009097:Multienzyme Complexes; C008757:palmitoleic acid; D019308:Palmitic Acid; D044943:Fatty Acid Desaturases; C433487:stearoyl ACP desaturase, Arabidopsis; D000123:Acetyltransferases; D013869:Thiolester Hydrolases; C018748:oleoyl-(acyl-carrier-protein) hydrolase; D054889:Fatty Acid Synthase, Type II