Understanding the functional role of cell wall-degrading enzymes in Magnaporthe oryzae and their interactions with...

Rice blast disease, caused by the hemibiotrophic fungus Magnaporthe oryzae, poses a major threat to global rice production. The plant cell wall serves as a primary defensive barrier against pathogen invasion; therefore, M. oryzae secretes an array of cell wall-degrading enzymes (CWDEs), predominantly members of the glycoside hydrolase (GH) family, to facilitate host colonization. However, CWDE-mediated cell wall degradation also leads to the release of damage-associated molecular patterns (DAMPs), which are perceived by surface-localized pattern recognition receptors, thereby activating defense responses in rice. While the role of CWDEs in cell wall degradation is well established, their contributions to host immune activation and the corresponding host countermeasures remain largely understudied. In this review, we elucidate the functional roles of key GH family proteins involved in the degradation of cellulose, hemicellulose, and pectin, as well as non-GH enzymes such as cutinases, in facilitating host invasion. We also discuss the immunogenic consequences of various CWDE activities, along with their secretion dynamics and transcriptional regulation. Furthermore, we present insights into host defense strategies, including cell wall fortification and the deployment of CWDE-targeting inhibitors. Together, these perspectives provide a comprehensive understanding of the role of CWDEs in regulating host-pathogen interactions and support the development of innovative strategies to enhance resistance against M. oryzae and related fungal pathogens.