Biocontrol of Plant Pathogens and Plant Growth Promotion by Bacillus

Numerous Bacillus strains have been investigated for their capacities to protect plants from pathogens and stimulate plant growth. Studying the diversity of these bacteria provides clues to the distinctiveness of beneficial strains and raises questions regarding the scale and evolutionary forces that led to the development of biocontrol activities. Soils harbor vast spore banks of Bacillus, subsets of which germinate, propagate or go dormant in patches varying size according to the availability of various resources. While the genus as a whole does not seem to be as competitive as some other genera, there do appear to be strains that are truly rhizosphere competent. Those that are will be well positioned to access resources and express activities that can lead to plant disease suppression and/or directly stimulate plant growth. It is now known that many different types of secreted products can affect both pathogens and plants in a variety of ways, all of which might lead to reductions in disease development. A greater understanding of this genus will help to accelerate the development and application of active strains and their products into biopesticidal products that improve crop quality and yields.