Caracterización y mapeo de genes de lipoxigenasas de trigo candeal.

SORESI D., ; CARRERA A., ; ROMERO J.,; RONCALLO P.,; ECHENIQUE V.; GARBUS I

Congreso; XXXIX Congreso de la Sociedad Argentina de Genética; 2010

Durum wheat (Triticum turgidum L. ssp. durum, genomes AABB) constitutes the cereal of preference for semolina and pasta production. A bright yellow color is an important quality criterion for pasta making. Yellow color depends on the amount of carotenoid pigments in grain, which is the result of the balance between pigment synthesis and degradation, mainly by lipoxygenases (LPX). The number and location of lipoxygenases genes in durum wheat (Triticum turgidum L. ssp. durum) genome is not completely understood. Our laboratory recently reported the existence of a duplication at the Lpx-B1 locus (Lpx-B1.1 and Lpx-B1.2), mapped on chromosome 4B, and associated the deletion of the Lpx-B1.1 copy, with a reduction in lipoxygenase activity. A second lipoxygenase locus, Lpx-A3, associated with better semolina and pasta color was mapped on the homoeologous region on chromosome 4A (Carrera et al., 2007). We further established the physical organization of Lpx loci in chromosomes 4A and 4B and identified a partially deleted copy of Lpx-1 in chormosome 4A (Lpx-A1_like), that colocalized within a 42 kbp region with Lpx-A3, confirming that in both genomes these two genes are close to each other (Garbus et al., 2009).The knowledge of the physical location of these Lpx genes is important to understand the evolution of this family but also has practical implications for breeding since closely linked genes are difficult to separate by recombination. OBJECTIVE This study was performed in order to extend the comprehension of lipoxygenase genes organization in tretraploid wheat genome.