Defense-Related Proteins in Sugarcane and Their Role in Disease Resistance: Molecular Advancements and Beyond

Sugarcane is the major agro-industrial crop, which not only fulfills 80% of the world’s sugar needs but is also a valuable source of bioenergy. Crop yield and sugar recovery are continuously under threat owing to consistent infestation by diseases and insect pests. Plants respond to pathogen infection by the activation of constitutive or inducible defense systems, including expression of defense-related proteins, i.e. chitinase, glucanase, chitosanase, metallothionine, peroxidase, thaumatin, and endoproteinase. These pathogen-induced proteins are directly or indirectly involved in plant defense response. Other plant proteins involved in the plant defense system are NBS-LRR, glycoproteins, catalases, and WRKY proteins. Pathogenic diseases are recognized by NBS-LRR, and it induces the production of glycoproteins after infection, which disrupts the physiological activity of the pathogens and make them inactive. Likewise, catalases are involved in the detoxification of reactive oxygen species (ROS). WRKY transcription factors play a crucial role in plant defense systems by regulating PR genes. Molecular interventions provide a swift solution to combat these stresses. Various endogenous genes have been explored in sugarcane to play a pivotal role in biotic stress tolerance. Efforts have also been made to develop GMOs having the potential to survive fungal pathogen infections. Few have reached the commercialization scale, whereas others are at the infancy stage. This chapter highlights defense-related proteins in sugarcane and their potential role to mitigate pathogen infestation through advancements in molecular biology.