Expressed variants of Δ12-fatty acid desaturase for the high oleate trait in spanish market-type peanut lines

López, Y. and Nadaf, H.L. and Smith, O.D. and Simpson, C.E. and Fritz, A.K. (2002) Expressed variants of Δ12-fatty acid desaturase for the high oleate trait in spanish market-type peanut lines. Molecular Breeding, 9 (3). pp. 183-190.

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Increasing the oleic to linoleic acid ratio (O/L) in peanut has positiveeffects on peanut quality and its nutritional value. 12-Fattyacid desaturases (12-Fad) have been targeted as logicalcandidates controlling the high oleate trait. A previous study using genomicDNA identified an insertion and a polymorphism resulting in an amino acid changeassociated with the high oleate trait in Spanish-type peanut cultivars. Theobjectives of this research were to use RT-PCR to confirm that the SingleNucleotide Polymorphims (SNPs) identified by analysis of genomic DNA wereexpressed, and to determine if expression patterns for 12-Fadwere the same in both seeds and leaves. A polymorphic region of the12-Fad containing a series of nucleotide changes wasamplified, cloned, and sequenced from mRNA of 155 clones of two parental linesand their independent derived backcross lines (IDBLs). The latter differed intheir oleic to linoleic ratio. Data indicated that the Ainsertion and the amino acid change were expressed in both leaf and seed tissue of thehigh and low-intermediate O/L genotypes. It is postulated that several copiesof the 12-Fad are present in the genome. It is reasonable toconclude that total activity, and ultimately the O/L ratio, is dependent on thenumber of functional copies. The results provide the basis for an assay toscreen for the high O/L ratio at the molecular level. We also report thepresence of another isozyme of 12-Fad with high homology tosoybean isozyme 2 that was expressed in seeds.

Item Type: Article
Additional Information: We express our thanks to Metinee Srivatanakul and Piyawit Bureekharm for their dedication and carefulness preparing individual seeds for oil analysis, and to Sam A. Reddy and Jim Connell for their technical help. This work was supported in part by The Texas Peanut Producers Board and The Peanut CRSP, and US Agency for International Development, under grant Number DAN-4048-G-0041-00. The experiments performed for this publication comply with the current status of USA’s laws.
Uncontrolled Keywords: �12-Fatty acid desaturase, Arachis hypogaea, Linoleic acid, Oleic acid, Peanut, RT-PCR, Single nucleotide polymorphism
Author Affiliation: Department of Soil and Crop Sciences, Texas A&M University, USA University of Agricultural Sciences,India Texas Agricultural Experimental Station, Texas A&M University,USA 4Department of Agronomy, Kansas State University,USA
Subjects: Plant Production
Statistics and Experimentation > Experimentation
Plant Physiology and Biochemistry > Biochemistry
Divisions: Groundnut
Depositing User: Mr Arbind Seth
Date Deposited: 13 Oct 2012 08:52
Last Modified: 13 Oct 2012 08:54
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