Plant growth promoting bacteria as biocontrol agents against diseases of cereal crops

Worldwide, huge amount of food commodity losses are reported annually due to plant diseases caused by various kinds of pests or pathogens. The continuous and indiscriminate use of chemical pesticides to control plant diseases is known to adversely affect the natural environment, plant and soil ecology as well as the human health by toxic chemical residues. In this context, researchers and farmers have attempted to explore some new eco-friendly and sustainable method for disease management. Plant growth promoting bacteria (PGPB) as biological control agents are such an effective and better alternative to chemical pesticides. PGPB are heterogeneous group of bacteria directly and indirectly involved in growth promotion and disease management in plants. PGPB deploy different biocontrol mechanisms of action that include production of antibiotics, antimicrobial or volatile compounds, cell wall–degrading enzymes, induced systemic resistance, etc. Through these biocontrol mechanisms, they effectively control some devastating plant diseases. Present review describes the biocontrol mechanism of PGPB with special reference to cereal crops.