Proceedings of the 53rd Italian Society of Agricultural Genetics Annual Congress Torino, Italy – 16/19 September, 2009 ISBN 978-88-900622-9-2 Poster Abstract – 5.12 FUNCTIONAL MARKERS FOR GLUTAMINE SYNTHETASE AND CORRELATION WITH GRAIN PROTEIN CONTENT IN DURUM WHEAT
NIGRO D., GADALETA A., GIANCASPRO A., BLANCO A.
Department of Agro-Forestry and Environmental Biology and Chemistry, University of Bari,Via Amendola 165/A, 70126 Bari, Italy
functional markers, glutamine synthetase, candidate gene, wheat
Durum wheat (Triticum turgidum L. var. durum) is one of the most important cereal crops
grown world-wide and provides most of the proteins in human diet, especially in the less developedcountries. Seed storage proteins are directly related to the nutritional and technological value of thederived products. Several studies have attested the key-role of the glutamine synthetase enzyme inplant nitrogen metabolism. Glutamine synthetase gene encodes for an enzyme responsible of thefirst step of ammonium assimilation and transformation into glutamine and glutamate, essentialcompounds in amino acid-biosynthetic pathway. High protein content is a very importantquantitative trait controlled by several genes located on wheat chromosomes. Glutamine synthetasegenes are located on the homeologous chromosomes 2A, 2B, and 2D where several authors reportedmajor QTL for protein content. The goal of the present study was to assess the linkage between GSgene and the QTL for protein content. For this purpose, the nucleotide sequence of glutaminesynthetase gene acc. DQ124214 was aligned to all the wheat ESTs available in public data bases bymeans of BLAST tool (http://www.wheat.pw.usda.gov/GG2/blast.shtml.). The bioinformaticanalysis allowed to find 40 sequences with a similarity > 94% to the GS2 gene, of which threecovered the whole gene sequence (DQ124213, DQ124212 and CJ705909). For each of thesesequences we designed two or three primer pairs identifying a total of 7 functional markers thatwere screened among the parents of three segregant populations. Mapping analysis performed byJoin Map software allowed to localize the amplified polymorphic fragments and to identify 4 loci:Gs-A2, Gs-B2, Gs-A4, Gs-B4, respectively mapped on chromosome 2A, 2B, 4A and 4B. The QTLanalysis for protein content was carried out in a RIL population obtained from the crossing the twodurum wheat cultivars Ciccio and Svevo. Two major QTLs were identified through CompositeInterval Mapping (CIM) performed by the Q-Gene software: one QTL was identified by thefunctional marker Gs-B2 located on chromosome 2B, and the other one was identified by thefunctional marker Gs-A4 located on chromosome 4A. These data were confirmed by a linkagedisequilibrium analysis carried on a collection of 75 different wheat genotypes.
The present study represents the first step for the identification and sequencing of GS2 gene,
which could be employed in breeding programs aimed to increase grain protein content commercialcultivars. Moreover, Gs-B2 and Gs-A4 represents functional markers that could be also efficientlyused in marker assisted selection (MAS) programs and map-based cloning.
THE NINTH CANDLE On both Purim and Chanukah we recite the Al HaNissim, and conclude with thanks and praise to Hashem. However, the Birchos Shivim points out a major distinction between the two holidays. On Chanukah there were revealed miracles, nissim gluyim . The many and strong army of the Greeks was defeated by the few and weak army of the Chashmona’im and the small cruse of oi
THE PRESIDENT’S ADDRESS Tena koutou, tena koutou, tena koutou katoa. E te whanau a te Karaiti. Naumai, haeremai, haeremai. I welcome you all to this third session of our fiftieth Synod, especially those of you who are here for the first time. As we meet together let us remember that although we are members of the Body of Christ, He, the Lord Jesus Christ, is the head of the Church.