Sequencing the psbA gene in Lolium multiflorum and atrazine tolerance assessment

MERINI, LJ; BOBILLO, C; CUADRADO, V; CORACH, D; GIULIETTI, AM

Mar del Plata - Buenos Aires

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (S.A.I.B.).; 2007

Some atrazine resistant plant species have agricultural application, which turns them into candidates for different phytoremediation strategies of this herbicide. A sequence change of D1 protein in the Photosystem II Reaction Center is one of the reported mechanisms of resistance to triazines. The substitution of the base A by G in the position 790 of psb A gene, causes the amino acid serine to be replaced by glycine in D1 protein, which is associated with resistance to triazine herbicides. The aim of this work is the selection of atrazine resistant plants with agronomical application and the characterization of the resistance mechanisms for their future use in phytoremediation. Tolerance assays were carried out and, among several candidates, Lolium multiflorum exhibited tolerance to atrazine at concentration above of the agronomical application rate. Total DNA was extracted in CTAB medium and purified. The fragment between position 612 and 835 was amplified by PCR, purified and sequenced in an automatic platform. Further, the whole gene was amplified, purified and sequenced. Lolium m. showed no mutation at the 790 position, hence, resistance is based on another mechanism, which is been investigated. Primers designed for the fragment can be used for assessment of triazine resistance in multiples vegetal species. Sequence of psb A gene will be registered into international databases