Response of ROS in Host Plant Assaulted by Opportunistic Fungi and Nematodes

The emergence of various abiotic and biotic stresses has become a major problem in practicing sustainable agriculture in recent years. Biotic stress such as fungi and nematodes continuously invades farmland causing a significant reduction in yield and quality of produce. Under stress conditions, the host plant’s biochemical pathway is disrupted bringing about abnormal responses and reactions in the plant to compensate for the stress encountered. Such responses include the production and accumulation of reactive oxygen species (ROS) within the plant cells which attack and damage all types of biomolecules. Furthermore, malondialdehyde and hydrogen peroxide are produced rapidly while antioxidant enzymes (enzymatic and non-enzymatic) production is reduced subsequently causing a decrease in crop productivity. The current book chapter is aimed at discussing biochemical responses in host plants assaulted by opportunistic fungi and nematodes. The role of antioxidant in scavenging ROS in plant and defense mechanisms against pathogen was also discussed.