Grapevine Crown Gall Suppression Using Biological Control and Genetic Engineering: A Review of Recent Research

Crown gall is a devastating grapevine disease often encountered in vineyards prone to winter cold injury. Agrobacterium vitis, the predominant causal agent of this disease, moves from the roots via xylem sap flow to freeze injury sites where genetic transformations then occur. Crown gall disrupts the grapevine trunk vascular system, which prevents nutrient flow and leads to plant decline and death. Viticultural practices designed to fight this disease are only partially effective, thereby requiring alternatives. Genetic engineering and biological control could be more desirable approaches for disease prevention. Biological control typically involves antagonistic organisms, which are applied to grapevine roots to reduce the concentration of pathogenic Agrobacterium strains. Genetic engineering may prevent infection and tumor formation by modifying grapevines and antagonistic organisms. In the grapevine, this may be achieved by enhancing molecular mechanisms for producing bacterium-specific antimicrobial peptides or preventing transferred deoxyribonucleic acid export, integration, and oncogene expression. Alteration of antagonistic organisms enhances the production of bacteriocins effective against agrobacteria. This article reviews the potential use of biological control options and genetic engineering tools for grapevine crown gall suppression and makes recommendations for further use and research.