Title : Role of microbial secondary metabolites in the management of plant diseases
Abstract:
Synthetic chemical pesticides are the first choice for the farmers when it comes to protect their crops against pests. This is mainly because of their efficiency in killing the pests, rapidity in effect and easy availability. However, these chemicals pose serious threat to human health and the environment. Non-judicious use of chemical pesticides leads to pollution of soil and water, health hazards due to residual toxicity and sometimes, development of resistance in pathogens against these chemicals making them useless. These concerns lead to search for alternate sources of chemicals that are natural, easily biodegradable and do not harm the environment. Thus, microbial metabolites emerge as an excellent source of active compounds that are antimicrobial and do not harm the environment as does the synthetic chemical do. Antibiotics are well known such anti-microbial metabolites derived from the microbes such as bacteria and fungi and are widely used in the pharmaceutical industry. Metabolites Koninginin D, 6-pentyl-2H-pyran-2-one and Gliotoxin from the species of fungi Trichoderma are effective against the pathogens like Rhizoctonia solani, Sclerotium rolsfii, Fusarium spp. etc. Similarly metabolites Bacillomycin D, Bacillin and Iturin A are derived from the species of the bacteria Bacillus and are effective against several soil borne pathogens. The microbial metabolites depending upon their stability are used as such in their naturally available form or used for synthesizing derivatives with more potent and stability.
