Assessing the mechanisms of atrazine tolerance of Lolium multiflorum: a phytoremediation approach

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

Villa Carlos Paz - Córdoba

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (S.A.I.B.).; 2008

As a new technology, phytoremediation is a low cost, environmental friendly biotechnological solution for atrazine (ATZ) pollution. Hence, the finding of ATZ tolerant plants and elucidation of the mechanisms involved in tolerance are crucial for designing remediation projects. Due to its agronomical properties and physiology, Lolium multiflorum (ryegrass) is one of the main candidates. The objective of this work is to assess the ATZ tolerance of ryegrass and the mechanisms involved in the process. Thus, ryegrass ATZ tolerance was assessed in MS agar medium with increasing herbicide levels. Then, the mechanisms involved in ATZ tolerance such as mutation psbA gene, enhanced enzymatic detoxification via P450 or chemical hydrolysis by benzoxazinones (Bx) were evaluated. Mutation in the psbA gene, encoding the ATZ target site D1 protein was evaluated by sequencing. The enzymatic detoxification was assessed in hydroponics cultures, exposing plants to ATZ and 1-aminobenzotriazole (P450 inhibitor). For Bx, the hydrolytic capacity of plant extracts on ATZ was tested. L. multiflorum was found as new tolerant specie, able to grow in presence of 1 mg Kg-1 of ATZ. The sequence for psbA gene was registered on GenBank. Atrazine tolerance is conferred in this specie by enzymatic detoxification via P450. Ryegrass is an excellent option for phytoremediation of agricultural ATZ contaminated soils