Interaction between TaNOX7 and TaCDPK13 Contributes to Plant Fertility and Drought Tolerance by Regulating ROS Production

Reactive oxygen species (ROS) homeostasis is critical for both physiological processes and stress responses of plants. NADPH oxidases (NOXs) are the key producers of ROS in plants. However, their functions in ROS homeostasis and plant growth regulation in wheat (Triticum aestivum) are little investigated. Here, we cloned and characterized a NOX isoform TaNOX7 in wheat. Overexpression of TaNOX7 in rice led to enhanced root length, ROS production, drought tolerance as well as bigger panicles and higher yield but shorter growth period duration. Further results indicate that TaCDPK13, a member of calcium-dependent protein kinases (CDPKs), can directly interact with TaNOX7 and enhance ROS production in plants. These results demonstrate that TaNOX7 plays crucial roles in wheat development, fertility, and drought tolerance via interaction with TaCDPK13, which may act as an upstream regulator of TaNOX7 to regulate ROS production in wheat.