Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 5.20

Characterisation of the enzymes involved on carotenoid pigment biosynthesis

A. Cenci, S. Somma, A. Blanco

Dipartimento di Biologia e Chimica Agro-Forestale e Ambientale, Università degli Studi di Bari, Via G. Amendola 165/A, 70126 Bari, Italy

durum wheat, carotenoid, sequence analysis, EST, BAC library

Breeding for durum wheat quality mainly concerns protein quantity and quality and carotenoid pigment content to give appreciable end-products. Carotenoid pigments confer to pasta the yellow amber colour requested and have also an antioxidant activity against photo-oxidant effects of light energy and against free radicals. These characteristics make them important components for their commercial, nutritional and healthy value. Semolina pigment content is a quantitative trait with high heritability values. It is controlled by QTL detected on several chromosomic groups.

Several enzymes are involved in carotenoid biosynthesis: nucleotidic sequence of these enzymes are available in gene databases for many species, but not for wheat. To identify the structure of these genes, comparison was performed by using mRNA and genomic sequences from different species. Rice, maize or Arabidopsis sequences were used to select wheat Expressed Sequence Tags (EST) on which specific primers were designed. A durum wheat Bacterial Artificial Chromosome (BAC) library was screened by Polimerase Chain Reaction (PCR) and BAC clones containing sequences for the carotenoid pathway enzymes were isolated. For each enzyme, BAC clones deriving from different genomes were distinguished by length polymorphism, conformation-sensitive gel electrophoresis or enzymatic restriction pattern. Chromosomal localisation was performed by using Langdon substitution line set. Sequencing and genetic mapping will be performed for the most interesting genes.