Expression of a functional antizearalenone single-chain Fv antibody in transgenic Arabidopsis plants

The efficacy of cloning a recombinant mycotoxin antibody in plants was test ed using Arabidopsis as a model. An antizearalenone single-chain Fv (scFv) DNA fragment was first cloned in the newly constructed phage display vector (pEY.5) and then recloned in the plant transformation vector pKYLX71::35S( 2). After transformation, constructs of antizearalenone scFv were introduce d into immature Arabidopsis seeds via Agrobacterium tumefaciens mediation b y vacuum infiltration. Only plants transformed with the construct containin g a PR-lb signal peptide sequence produced transgenic offspring. The antize aralenone scFv "plantibody" from these transgenic plants bound zearalenone with a high affinity (50% inhibitory concentration, 11.2 ng/ml) that was co mparable to that of bacterially produced scFv antibody and the parent monoc lonal antibody (MAb). By electron microscopic immunogold labeling, the pres ence of antizearalenone scFv was detected mainly in the cytoplasm and only occasionally outside the cell. Like bacterially produced scFv antibody, ant izearalenone scFv plantibody exhibited greater sensitivity to methanol dest abilization than did the parent MAb, The sensitivity of antizearalenone scF v plantibody to acidic disassociation was similar to the sensitivities of b acterially produced scFv antibody and MAb, Expression of specific plantibod ies in crops might be useful for neutralizing mycotoxins in animal feeds an d for reducing mycotoxin-associated plant diseases.