Plant cell walls, beyond their structural role, play a crucial role in plant adaptation to environmental conditions and defense against pathogens. These walls are dynamic structures that can alter in composition and integrity in response to stress and developmental cues. Changes in wall structure are perceived by plant sensors, triggering adaptive responses. Pathogen infection or wounding can damage the cell wall, releasing glycans that function as damage-associated molecular patterns (DAMPs) or microbe-associated molecular patterns (MAMPs). MAMPs and DAMPs are recognized by pattern recognition receptors (PRRs), activating pattern-triggered immunity (PTI) and disease resistance. The recognition of these glycans by PRRs, particularly those of the LysM-PRR family, has been well studied. However, other PRR families, such as receptor kinases (RKs) with leucine-rich repeat and Malectin domains, have also been implicated in oligosaccharide/polysaccharide recognition. The characterization of these receptors and their interactions with glycans will provide insights into their structural mechanisms and potential applications in sustainable crop protection. The composition and structure of plant cell walls vary significantly between different plant species and tissues, influenced by factors such as phylogenetic group and tissue specialization. These variations affect the mechanical properties and defense mechanisms of plants. For example, alterations in cell wall components like pectins, hemicelluloses, and lignin can influence disease resistance. Mutants with altered cell wall structures exhibit specific resistance phenotypes to various pathogens, highlighting the importance of cell walls in immunity. Cell wall modifications caused by pathogens can trigger defensive responses, and mutations affecting cell wall-related genes can lead to altered wall composition and increased disease resistance. For instance, mutants impaired in cellulose synthesis show enhanced resistance to certain pathogens, while those with altered pectin content exhibit resistance to different pathogens. Callose, a β-1,3-D-glucan, also plays a crucial role in plant defense by forming barriers at sites of fungal penetration. The activation of immune pathways in response to cell wall alterations is not always through canonical signaling pathways. Some mutants display enhanced resistance that cannot be explained by upregulation of canonical PTI or phytohormone-related genes. Instead, alternative pathways, such as brassinosteroid- and strigolactone-mediated signaling, may be involved. The release of DAMPs and MAMPs from cell walls and microbial extracellular layers is a key aspect of plant defense. These glycans can be recognized by PRRs, triggering PTI and disease resistance. Pre-treatment of plants with DAMPs or MAMPs can boost defense responses, as evidenced by transcriptomic reprogramming and enhanced resistance to pathogens. However, the full diversity of uncharacterized DAMPs and MAMPs remains to be explored. Maintaining homeostasis of DAMPs and MAMPs is essential to prevent hyper-immunity and potential cell death. Enzymes likePlant cell walls, beyond their structural role, play a crucial role in plant adaptation to environmental conditions and defense against pathogens. These walls are dynamic structures that can alter in composition and integrity in response to stress and developmental cues. Changes in wall structure are perceived by plant sensors, triggering adaptive responses. Pathogen infection or wounding can damage the cell wall, releasing glycans that function as damage-associated molecular patterns (DAMPs) or microbe-associated molecular patterns (MAMPs). MAMPs and DAMPs are recognized by pattern recognition receptors (PRRs), activating pattern-triggered immunity (PTI) and disease resistance. The recognition of these glycans by PRRs, particularly those of the LysM-PRR family, has been well studied. However, other PRR families, such as receptor kinases (RKs) with leucine-rich repeat and Malectin domains, have also been implicated in oligosaccharide/polysaccharide recognition. The characterization of these receptors and their interactions with glycans will provide insights into their structural mechanisms and potential applications in sustainable crop protection. The composition and structure of plant cell walls vary significantly between different plant species and tissues, influenced by factors such as phylogenetic group and tissue specialization. These variations affect the mechanical properties and defense mechanisms of plants. For example, alterations in cell wall components like pectins, hemicelluloses, and lignin can influence disease resistance. Mutants with altered cell wall structures exhibit specific resistance phenotypes to various pathogens, highlighting the importance of cell walls in immunity. Cell wall modifications caused by pathogens can trigger defensive responses, and mutations affecting cell wall-related genes can lead to altered wall composition and increased disease resistance. For instance, mutants impaired in cellulose synthesis show enhanced resistance to certain pathogens, while those with altered pectin content exhibit resistance to different pathogens. Callose, a β-1,3-D-glucan, also plays a crucial role in plant defense by forming barriers at sites of fungal penetration. The activation of immune pathways in response to cell wall alterations is not always through canonical signaling pathways. Some mutants display enhanced resistance that cannot be explained by upregulation of canonical PTI or phytohormone-related genes. Instead, alternative pathways, such as brassinosteroid- and strigolactone-mediated signaling, may be involved. The release of DAMPs and MAMPs from cell walls and microbial extracellular layers is a key aspect of plant defense. These glycans can be recognized by PRRs, triggering PTI and disease resistance. Pre-treatment of plants with DAMPs or MAMPs can boost defense responses, as evidenced by transcriptomic reprogramming and enhanced resistance to pathogens. However, the full diversity of uncharacterized DAMPs and MAMPs remains to be explored. Maintaining homeostasis of DAMPs and MAMPs is essential to prevent hyper-immunity and potential cell death. Enzymes like