Bacillus Species: Excellent Biocontrol Agents against Tomato Diseases

Abstract

Tomatoes encounter many pathogens, such as fungi and bacteria, which reduce the yield and quality of plants and lead to large losses in production. The application of plant protection products (PPPs) is still an important and most effective measure to control plant diseases. However, the use of chemicals in agriculture contributes to environmental pollution and biodiversity loss, and it can also threaten non-target living organisms. Biological control is a widely accessible, environmentally safe, and cost-efficient alternative for the prevention and suppression of plant diseases. Bacillus species with antimicrobial and plant growth-promoting effects are most frequently used as biocontrol agents to increase the resilience of agricultural production against biotic stresses. The present review discusses the antagonistic mechanisms and the biocontrol potential of Bacillus spp. against tomato diseases caused by different pathogens. The main mechanisms of Bacillus spp. include the production of antimicrobial compounds (antibiotics, extracellular enzymes, siderophores, and volatile compounds), competition for nutrients and space, and induced systemic resistance (ISR). Although Bacillus-based PPPs have been developed and commercialised worldwide for various crops and pathogens, the efficiency issues are still subject to debate. Additionally, a combined strategy for controlling tomato diseases based on Bacillus spp. and other available methods (conventional or natural-based) is a promising research field.

Biocontrol Potential of Bacteria Isolated from Vermicompost against Meloidogyne incognita on Tomato and Cucumber Crops

“…Bacillus-like bacteria are ubiquitous in various habitats in nature, and they have strong environmental adaptability. They are a valuable type of biocontrol bacteria for plant diseases and insect pests and can effectively promote the growth and development of plants [42,43]. The action mechanism of Bacillus in controlling plant root-knot nematodes is (1) to compete for nutrients and space; (2) to alter the action mode of root exudates and nematodes; (3) to produce toxic substances that are fatal for root-knot nematodes; and (4) to generate secondary metabolites that inhibit egg hatching and larval development [44].…”

Bio-Priming with Bacillus Isolates Suppresses Seed Infection and Improves the Germination of Garden Peas in the Presence of Fusarium Strains

“…Therefore, a series of strategies based on seed treatments with biocontrol agents (BCAs) have been developed to prevent the application of synthetic pesticides and to reduce the detrimental effects of agrochemicals on the environment and human health [11]. Biological control is a widely available, environmentally friendly, and inexpensive method for the suppression of plant pathogenic microorganisms, and is of special importance in organic vegetable production [12]. Bacillus spp.…”

“…Bacillus spp. with antimicrobial activities are most commonly employed as BCAs to increase crop resilience against biotic stresses [12,13]. These bacteria are highly advantageous in achieving desired biocontrol effects, along with stimulating the growth and development of the host plant.…”