Essential Oils as Antimicrobial Agents Against Some Important Plant Pathogenic Bacteria and Fungi

Abstract

Plant diseases impact negatively on human well-being through agricultural and economic loss and also have consequences for biodiversity conservation. They are caused by some pathogens like bacteria, fungi, nematodes and viruses. Bacteria and fungi are the most common cause of many diseases of plants. The use of antibiotics for the control of plant diseases is limited due to the possibility to the production of some pathogen populations resistant to fungicides and pathogen populations resistant to antimicrobial agents and the ability to the transfer of responsible resistant genes to human and animal pathogenic microbes. In addition, these chemical compounds can cause undesirable effects on environment due to their slow biodegradation and several serious side effects on mammalian health associated to toxic residues in agricultural products. There is, therefore, a need to develop alternative control agents to pathogenic bacterial and fungal diseases in plants. Essential oils are a concentrated hydrophobic liquid containing volatile aroma compounds derived from the different parts of the plants. They were previously known to possess many biological activities such as antifungal and antibacterial properties. In addition, the potential effectiveness of essential oils against many plant pathogenic bacteria and fungi has been verified by many authors. This review discusses the susceptibility of most important ten bacterial and fungal plant pathogens towards different essential oils and their constituents, which have been reported in scientific references.