Role of Plant Growth Promoting Rhizobacteria in Biocontrol of Plant Diseases and Sustainable Agriculture

Abstract

The management of plant diseases in the sustainable agriculture has become a challenge for plant pathologist. Increasing knowledge and growing concern of pesticide applications on environment have aroused interest in alternative methods of plant protection. Plant growth promoting rhizobacteria (PGPR) are the important group of microorganisms, which play a major role in the biocontrol of plant pathogens. PGPR can profoundly improve seed germination, root development, and water uptake by plants. These rhizobacteria stimulate plant growth directly by producing growth hormones and improving nutrient uptake or indirectly by changing microbial balance in favor of beneficial microorganisms in the rhizosphere and can suppress a broad spectrum of bacterial, fungal, nematode, and even some viral diseases. Although significant control of plant pathogens has been demonstrated by PGPR in laboratory and greenhouse studies, results in the field trials have been inconsistent. Recent progress in our understanding of their diversity, colonizing ability, and mechanisms of action, formulation, and their application may facilitate their development as reliable biocontrol agents against plant pathogens. Use of PGPR has become a common practice in many regions of the world, and greater application of PGPR is possible for sustainable agriculture in near future.