Isolation of Bacteria with Biocontrol Activity Against Phytopathogens: Dual Plate Assay

Abstract

Biological control briefly noted as biocontrol has been used in different fields of biology especially in entomology and plant pathology. In plant pathology, the microbial antagonists suppress the diseases. The organism which is used to suppress the pest or pathogen is referred as biological control agents (BCA). If BCA is a microorganism, then it is referred as microbial biological control agents (MBCA). The MBCAs have a wide mode of action against the pathogenic organisms. MBCAs interact with plants by inducing its resistance. They create nutrient competition to pathogens or involving with other mechanisms which disturbed the growth of the pathogens. The stimulation of plants defense mechanisms by MBCA is mainly dependent on the plant genotypes. Plants enhance the defensive capacity to multiple pathogens by beneficial microbes, various mechanisms like reactive oxygen species, phytoalexins, phenolic compounds/pathogenesis-related proteins (PR proteins), and strategies like physical barriers (cell wall/cuticle modifications) by induced plants and secretion of volatile organic compounds. Dual plate assay, a confrontation assay against the plant pathogens is inhibited by antagonistic bacteria.