Increasing expression of an anti-picloram single-chain variable fragment (ScFv) antibody and resistance to picloram in transgenic tobacco (Nicotiana tabacum).
Systematic research involving four chimeric gene constructions designed to express the same anti-picloram single-chain variable fragment (scFv) antibody is described. Agrobacterium-mediated transformation produced at least 25 transgenic tobacco plants with each of these, and the number of T-DNA loci in each plant was determined using kanamycin-resistance segregation assays. The relative amounts of active and total scFv in each plant were evaluated using quantitative enzyme-linked immunosorbent assay and immunoblot technologies, respectively. No significant differences in scFv activity were found among the four groups of single-locus plants, although the 35S/M construct was found to produce significantly more total anti-picloram scFv than the other three constructs. A dose-response bioassay involving T(1) seedlings from several of the highest expressers of active scFv demonstrated resistance to a constant exposure of picloram at 5 x 10(-)(8) M. Other approaches for increasing antibody-based herbicide resistance are discussed, as further improvements are needed before practical application of this technology.
Olea-Popelka
Fernando
F
Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada.
McLean
Michael D
MD
Horsman
Jonathan
J
Almquist
Kurt
K
Brandle
Jim E
JE
Hall
J Christopher
JC
D001483:Base Sequence; D004351:Drug Resistance / Q000235:genetics; D015870:Gene Expression; D006540:Herbicides; D007135:Immunoglobulin Variable Region / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D010846:Picloram / Q000276:immunology* / Q000494:pharmacology*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000276:immunology*; D014026:Nicotiana / Q000187:drug effects / Q000276:immunology*
D006540:Herbicides; D007135:Immunoglobulin Variable Region; D010846:Picloram