Volume No. 3 Issue No.: 3 Page No.: 859-866 Jan-Mar 2009

 

DETECTION AND PERSISTENCE OF Bt TOXIN IN DECOMPOSITION STUDY OF Bt LEAVES OF TRANSGENIC COTTON

 

Namita Rani Das*, Anita Chaudhary, R. Choudhary and H.C. Joshi

Division of Environmental Sciences, Indian Agricultural Research Institute, Pusa, New Delhi (INDIA)

 

Received on : November 04, 2008

 

ABSTRACT

 

Genetically engineered plants and their residues may pose direct or indirect impacts on different ecosystem functions. The aim of this experiment was to determine the decay rates of Bt and non-Bt cotton leaves and to determine the rate at which the Bt-?-endotoxin in Bt cotton leaves decomposes in soil. In laboratory incubation study Bt and non-Bt cotton leaves were added to a soil in which Bt cotton was cultivated for last three years (termed as Bt soil) and to another soil where transgenic crops were never cultivated (termed as Bulk soil). Different amount of leaf residues viz; 0%, 0.1%, 0.5%, 1%, 2% added to both the soil which represented varied amount of Cry1Ac (Bt toxin) viz; 0 ?g/g, 0.17 ?g/g, 0.8 ?g/g, 1.7 ?g/g, 3.4 ?g/g which was quantified by ELISA (Enzyme Linked Immunosorbent Assay). In 73 days incubation study, there was less CO2 evolution rate from Bt leaves in comparison with non Bt leaves in both of the soil. Simultaneous quantification study of Bt toxin (Cry1AC) from both of the soil (sampled from the incubation experiment) at different steps reveals longer persistence of Bt toxin in soil where Bt cotton was cultivated for long time rather than that of Bulk soil (never cultivated with Bt crops). The result suggested that though Bt toxin decomposes in soil but can persist in soil if cultivated for long time and Bt leaves are more recalcitrant in comparison with non Bt cotton leaves which may indirectly impact on soil fertility status due to low mineralization rate.

 

Keywords : Bt toxin, Persistence, Decomposition, ELISA, ?-endotoxin.?

 

 

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