Benzoic Acid and Its Derivatives: Protectors Against Plant Stress

Benzoic acid and related substances are phenolic compounds that help plants resist the harmful effects of salinity (soil or irrigation water), water stress (flooding or drought), temperature extremes (heating or chilling), and heavy metal stress by enhancing various physiological processes and strengthening the plant’s immune system. Phenolic compounds are a type of non-enzymatic antioxidant that helps reduce lipid peroxidation and the formation of reactive oxygen species (ROS), maintaining an optimal balance between plant growth and stress defense. Additionally, benzoic acid and related substances show antimicrobial properties by inhibiting the growth of molds, yeasts, and bacteria, especially in acidic environments. Furthermore, benzoic acid is considered a plant allelopathic substance that accumulates in soil year after year due to its poor biodegradability. Using benzoic acid or its derivatives, such as salicylic acid, p-hydroxybenzoic acid, gallic acid, and sodium benzoate, in small amounts has great potential as a management tool to help crops achieve higher yields under various biotic and abiotic stresses. This chapter focuses on the role of benzoic acid and its derivatives in protecting different kinds of plants from biotic and abiotic stress due to their role in the formation of secondary metabolites, growth promoters, and acting as antitranspirants and antimicrobials. However, the physiological and biochemical mechanisms underlying these roles of benzoic acid and its derivatives are not well understood.