Antibody-based resistance to plant pathogens

Plant diseases are a major threat to the world food supply, as up to 15% of production is lost to pathogens. In the past, disease control and the gene ration of resistant plant lines protected against viral, bacterial or funga l pathogens, was achieved using conventional breeding based on crossings, m utant screenings and backcrossing. Many approaches in this field have faile d or the resistance obtained has been rapidly broken by the pathogens. Rece nt advances in molecular biotechnology have made it possible to obtain and to modify genes that are useful for generating disease resistant crops. Sev eral strategies, including expression of pathogen-derived sequences or anti -pathogenic agents, have been developed to engineer improved pathogen resis tance in transgenic plants. Antibody-based resistance is a novel strategy f or generating transgenic plants resistant to pathogens. Decades ago it was shown that polyclonal and monoclonal antibodies can neutralize viruses, bac teria and selected fungi. This approach has been improved recently by the d evelopment of recombinant antibodies (rAbs). Crop resistance can be enginee red by the expression of pathogen-specific antibodies, antibody fragments o r antibody fusion proteins. The advantages of this approach are that rAbs c an be engineered against almost any target molecule, and it has been demons trated that expression of functional pathogen-specific rAbs in plants confe rs effective pathogen protection. The efficacy of antibody-based resistance was first shown for plant viruses and its application to other plant patho gens is becoming more established. However, successful use of antibodies to generate plant pathogen resistance relies on appropriate target selection, careful antibody design, efficient antibody expression, stability and targ eting to appropriate cellular compartments.