Sustained Influences of Reactive Oxygen Species and Brassinosteroids on Photosynthetic Capability and Antioxidant Responses to Heat Stress in Wheat

However, the long-term implications of exogenous brassinosteroid (BR) treatment and its reliance on reactive oxygen species (ROS) is not well defined. We investigated how manipulating BR in germinating wheat alongside a ROS-inhibitor could affect yield component outcomes when plants were subjected to heat stress during reproduction.

Inhibiting BR reduced superoxide dismutase (SOD) activity, increased lipid peroxidation, and correlated with multiple yield component losses compared to controls following heat stress. Despite a greater initial reduction in effective photochemical yield and SOD activity during heat stress for BR-treated plants compared to controls, BR-treated plants had sustained SOD activity and photochemical capability over prolonged heat stress compared to continued losses observed in control plants.