Ferulic Acid: A Phenolic Compound for Plant Stress Resistance

Ferulic acid (FA), a hydroxycinnamic acid derivative abundant in plant cell walls, is a key metabolite within the phenylpropanoid pathway. It is increasingly recognized as a multifunctional compound modulating a wide spectrum of physiological responses to both abiotic (e.g., drought, salinity, extreme temperatures, elevated CO2, ozone, heavy metals) and biotic (e.g., bacterial and fungal pathogens, insects) stresses. Apart from its classical roles in lignification and cell wall reinforcement, FA participates in redox balance, signal transduction, and stress gene regulation. It contributes to plant immunity via antimicrobial activity, regulation of pathogenesis-related genes, and hormone signaling interactions. Under abiotic stress, FA acts as an antioxidant, regulates ion transport, and maintains membrane stability. This chapter examines FA biosynthesis, transport, molecular functions, and its role as a bioactive metabolite in plant defense and stress reduction. By incorporating recent discoveries and practical insights, we offer a systems-level understanding of FA’s role in plant resilience and its potential as a stimulant in stress-smart agriculture.