Yellow pigment content in durum wheat (TriticumturgidumL. ssp. durum) is an essentialfeature for both pasta yellow color and human health because of antioxidant properties ofcarotenoids involved in the yellow pigmentation.Carotenoids are the most important components of semolina yellow pigments and aresynthesized through a complex pathway, involving more than 10 enzymatic steps. Phytoenesynthase (Psy), catalizing the condensation of two geranylgeranyl pyrophosphate molecules intophytoene, is generally considered the rate-limiting enzyme in carotenoids biosynthesis. In the grassfamily, triplicated genes were identified and designated as Psy1, Psy2, and Psy3respectively.Phytoene synthase 1 showed effective association with the yellow pigment (YP) content in wheatgrain. Characterization of Psygenes and development of functional markers are important formarker-assisted selection in wheat breeding.One of the goals of this study is to develop functional markers based on the sequence of Psy2gene sand to map them in different segregant populations and a set of Chinese Spring nulli-tetrasomic, ditelosomic and deletion lines. To date no full-length DNA sequence of Psy2 has beencloned in either common or durum wheat. With the aim of clarifying the structure of Psy2gene inthe coding sequence region and identifying allelic variants at this locus, the CDS region wassequenced by cloning cDNA and reconstructing the 5'-UTR and 3'-UTR through 5' and 3'RACE-PCR. The A and B genome loci were easily discriminated by differences in the nucleotidesequence.Using the reconstructed sequences it will be possible to design primers able to amplify thewhole gene sequence, identify different alleles, and determine the association of allelic variantswith phenotypic variation for endosperm colour, in segregant populations and collections of wheatcultivars
PHYTOENE SYNTHASE 2 LOCI ( PSY2 ) IN DURUM WHEAT - MOLECULAR CHARACTERIZATION AND DEVELOPMENT OF FUNCTIONAL MARKERS FOR SEMOLINA COLOUR
2009
Abstract
Yellow pigment content in durum wheat (TriticumturgidumL. ssp. durum) is an essentialfeature for both pasta yellow color and human health because of antioxidant properties ofcarotenoids involved in the yellow pigmentation.Carotenoids are the most important components of semolina yellow pigments and aresynthesized through a complex pathway, involving more than 10 enzymatic steps. Phytoenesynthase (Psy), catalizing the condensation of two geranylgeranyl pyrophosphate molecules intophytoene, is generally considered the rate-limiting enzyme in carotenoids biosynthesis. In the grassfamily, triplicated genes were identified and designated as Psy1, Psy2, and Psy3respectively.Phytoene synthase 1 showed effective association with the yellow pigment (YP) content in wheatgrain. Characterization of Psygenes and development of functional markers are important formarker-assisted selection in wheat breeding.One of the goals of this study is to develop functional markers based on the sequence of Psy2gene sand to map them in different segregant populations and a set of Chinese Spring nulli-tetrasomic, ditelosomic and deletion lines. To date no full-length DNA sequence of Psy2 has beencloned in either common or durum wheat. With the aim of clarifying the structure of Psy2gene inthe coding sequence region and identifying allelic variants at this locus, the CDS region wassequenced by cloning cDNA and reconstructing the 5'-UTR and 3'-UTR through 5' and 3'RACE-PCR. The A and B genome loci were easily discriminated by differences in the nucleotidesequence.Using the reconstructed sequences it will be possible to design primers able to amplify thewhole gene sequence, identify different alleles, and determine the association of allelic variantswith phenotypic variation for endosperm colour, in segregant populations and collections of wheatcultivarsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
