Creation of disease-resistant plants by gene engineering

Publisher Summary The chapter describes approaches to obtain plants resistant against disease by means of genetic engineering by plant-pathogen interaction models. Genetic engineering is based on the technology enabling construction of genetic structures in the form of the so-called recombinant (hybrid) molecules (DNA or RNA) in laboratory conditions. The advantages of gene engineering technologies compared with traditional hybridization are (1) hybridization impoverishes the whole genomes of the two parents, and (2) hybridization enables transgenosis only from closely related plants that have no reproduction barriers. Methods of transgenic plant creation include the use of pTi plasmids, use of intermediate vectors, use of binary vectors, pRi plasmids, method of biological ballistics, electroporation, transformation of plant protoplasts, microinjections, and marker genes for transformant selection. The chapter explains transformant regeneration and the development of transgenic plants resistant to viral disease. Some of them are the resistance provided by the expression of the viral coat protein in a plant gene, such as cross-protection of plants against viral infection and transgenosis of viral protein; resistance of transgenic plants induced by expression of transport proteins; and resistance of transgenic plants induced by expression of antiviral antibodies. The chapter also discusses the development of transgenic plants resistant to fungal and bacterial diseases by way of genetic engineering. It also discusses the development of nonplant antibacterial proteins. Mechanisms responsible for susceptibility or resistance in plant–bacterium relationships include general resistance and specific resistance. Some of the topics that are discussed under the sectionon enhancement of natural plant defenses are enhanced production of elicitors, expression of cloned resistance genes, enhanced production of reactive oxygen species, and so on. This chapter also explains the possible limitations of the commercial use of bioengineering methods in the creation of plants resistant to bacterial diseases.