Microbial volatiles as chemical weapons against pathogenic fungi

Abstract

The soil is one of the main habitations of fungi and bacteria. Their interactions are part of a communication web that keeps microhabitats in balance in this amphitheater. Protuberant negotiator molecules of these inter- and intra-organismic relationships are inorganic and organic microbial volatile compounds (MVOCs). Various mixtures of gas-phase and carbon-based compounds are called volatile VOCs produced by microbes and have the capability to diffuse through the atmosphere and soils due to their small size. The volatile organic compounds benzothiazole, cyclohexanol, n-decanal, dimethyl trisulfide, 2-ethyl-1- hexanol, and nonanal are emitted by microorganisms. VOCs have possible potential as an alternative to harmful pesticides, fungicides, and bactericides as well as genetic modification. They play an important role in the inhibition of sclerotial activity, limiting ascospore production, and reducing disease levels in plant pathogenic fungi. Their role as below- and aboveground signals has been established decadely. Recently it is suggested evidently that they might have an important role in below- and aboveground level and involved in microbial-root interactions. Similarly, microbial VOCs appear to be involved in antagonism, mutualism, intra- and interspecies regulation of cellular and developmental processes, and modification of their surrounding environments. Various researchers specify that the MVOCs might provide an alternative to the use of chemicals to protect plants from pathogens and provide a setting for better crop welfare. It is well known that MVOCs can modify the plant physiology and microorganisms. In this assessment, we suggest that MVOCs can be exploited as an eco-friendly, cost-effective, disease-resistant, and sustainable strategy for agricultural practices. Our effort is making a comprehensive chapter of below- and aboveground interactions of microbial volatile diversity and their role against pathogenic fungi.