Pectin‐Mediated Plant Immunity

The plant cell wall, a dynamic and complex structure surrounding every plant cell, serves not only as a passive structural barrier but also as an active monitoring system for protection against biotic and abiotic stresses. Plants monitor and maintain the status of their cell wall integrity (CWI) through the perception of signal molecules derived from pathogens or the plant cell walls themselves via pattern recognition receptors (PRRs) localised on the plasma membrane. PRRs in turn trigger a cascade of responses, including cell wall remodelling, to adapt to environmental stimuli. Pectin is the most abundant and structurally complex polysaccharide in the plant cell wall. Emerging evidence has revealed new features of pectin and challenged the classic primary cell wall model, providing an opportunity to revisit the role of pectin and CWI during plant–pathogen interactions. Here we present an overview of recent findings on the relationships between pectin metabolism and cell wall‐mediated immunity along with the underlying regulatory mechanisms. We propose future studies to reveal the fine structural and dynamic changes of specific wall polymers with improved temporal‐spatial resolution for a better understanding of pectin‐mediated plant immunity at the cellular and molecular level. Finally, we conclude that manipulating pectin composition and structure using advanced molecular breeding strategies, such as CRISPR editing technologies, can be a viable approach to develop novel crop genotypes with improved disease resistance.