rev phytopathol 28 451 coat protein mediated resistance has been conferred upon transformed plants against alfalfa mosaic virus cucumber mosaic virus tobacco streak virus potato virus x potato virus y tobacco etch virus tobacco rattle virus and tobacco mosaic virus id an insect specific antibody or an immunotoxin derived therefrom thus an antibody targeted to a critical metabolic function in the insect gut would inactivate an affected enzyme killing the insect gut cf taylor et al 1994 abstract 497 seventh international symposium on molecular plant microbe interactions 1994 disclosing enzymatic inactivation in transgenic tobacco via production of single chain antibody fragments a virus specific antibody see for example tavladoraki et al 1993 nature 366 469 showing that transgenic plants expressing recombinant antibody genes are protected from virus attack a developmental arrestive protein produced in nature by a pathogen or a parasite thus fungal endo u03b1 1 4 d polygalacturonases facilitate fungal colonization and plant nutrient release by solubilizing plant cell wall homo u03b1 1 4 d galacturonase see lamb et al 1992 bio technology 10 1436 the cloning and characterization of a gene that encodes a bean endopolygalacturonase inhibiting protein is described by toubart et al 1992 plant j 2 367 a developmental arrestive protein produced in nature by a plant for example logemann et al 1992 bio technology 10 305 have shown that transgenic plants expressing the barley ribosome inactivating gene have an increased resistance to fungal disease a herbicide that inhibits the.