Antimicrobial peptides (AMPs) of plant origin and their applications

Abstract

Plant Antimicrobial peptides (AMPs) are small, naturally occurring polypeptides, synthesized by the plants, as a fundamental component of their innate immune defense systems against a wide range of pathogenic microorganisms. In plants, AMPs are constitutively expressed or induced in response to several different biotic and abiotic stress factors. These peptides exhibit broad-spectrum antimicrobial activity against a wide range of pathogens, including Gram-positive and Gram-negative bacteria, viruses, fungi, and parasites. Structurally, plant AMPs are highly diverse and include several well-characterized families such as defensins, thionins, lipid transfer proteins, cyclotides, and hevein-like peptides, many of which are stabilized by disulfide bonds that enhance their stability and resistance to proteolytic degradation. The mechanism of action of AMPs typically involves disruption of microbial cell membranes, inhibition of cell wall synthesis, interference with intracellular targets, or modulation of pathogen signalling pathways, which reduces the likelihood of resistance development compared to conventional antibiotics. Due to their small size, structural diversity, rapid action, and effectiveness against multidrug-resistant pathogens, AMPs have emerged as promising candidates for the development of next-generation antimicrobial therapeutics. Furthermore, advances in peptide engineering, bioinformatics, and synthetic biology have enhanced the stability, specificity, and therapeutic potential of AMPs, highlighting their significance as viable alternatives to traditional antibiotics in addressing the global challenge of antimicrobial resistance.