Chapter 2 - Bacterial volatile organic compounds and gene-induced host-defense pathways

Abstract

The microbial volatile organic compounds (VOCs) directly and/or indirectly play a role in plant/fungi–microbe interactions. A number of different bacterial VOCs have been identified, comprising polyaromatic hydrocarbons. The characteristic profile of these compounds is attributed for activation of specific metabolisms in the bacteria. VOCs play significant roles in interspecific bacterial interactions. The biological and ecological functions of VOCs are diverse, depending on their role in bioconversion, mineralization of elements, metabolic reactions, quorum sensing/quenching, communication signals, and defense induction. Particularly, bacteria belonging to rhizobacteria species are able to promote plant growth and produce VOCs by using of root-exudates as a carbon source. Even these microorganisms have not been elucidated; the present available results indicate that VOCs of microbes are a good source for identification of novel volatiles that can provide ecofriendly alternatives to pesticides and fertilizers in the agriculture. In this review, we stress the role of these VOCs with their potential role and exploitation of them for induction of host defense in view of a host–pathogen interaction.