Chitin and laminarin additively trigger wheat reactive oxygen species but not resistance to Fusarium head blight.

Plants respond to fungal infections by activating defense genes including producing reactive oxygen species (ROS). The fungus causes Fusarium head blight (FHB), a serious disease of wheat and barley. FHB results in crop yield loss and contaminates grain with mycotoxins. In a prior study, we discovered that chitin induces tissue-specific ROS burst in wheat. However, it is unknown whether other fungal cell wall components could induce defense response in wheat. Therefore, we evaluated ROS and defense gene responses in different wheat tissues that had been treated with chitin, laminarin, or both. Different ROS patterns were induced in wheat treated with laminarin or chitin. Furthermore, we found that ROS were enhanced in wheat tissues treated with both chitin and laminarin. This study provides novel information for enhancing plat immunity to increase plant resistance.