Role of reactive oxygen species in infection of fungal and oomycete plant pathogens.

真菌NADPH氧化酶（Nox）调控活性氧（ROS）的合成在病原真菌和共生真菌与寄主植物的相互作用中起着关键作用。在本研究中，我们分离并研究了一种新的真菌Nox调节剂的功能。真菌Nox酶产生ROS需要由NoxA、NoxR和RacA组成的多亚基复合物的组装。相互作用实验表明，NoxR与RacA、BemA和Cdc24相互作用，Cdc42与BeinA相互作用。BeinA、Cdc24、NoxR和RacA优先定位于菌丝尖端。这些结果表明，真菌BemA和Cdc24在侵染寄主植物过程中，对Nox蛋白的定位和激活起关键作用，从而建立真菌菌丝细胞的极性。

Regulated synthesis of reactive oxygen species (ROS) by fungal NADPH oxidases (Nox) plays a key role in interactions of pathogenic and symbiotic fungi with host plants. In this study, we isolated and investigated the function of novel regulator of fungal Nox. Generation of ROS by fungal Nox enzymes requires assembly of a multi-subunit complex composed of NoxA, NoxR, and RacA. Interaction assays showed that NoxR interacts with RacA, BemA and Cdc24, and Cdc42 interacts with BeinA. BeinA, Cdc24, NoxR and RacA preferentially localized to hyphal tips. These results demonstrate that fungal BemA and Cdc24 play a critical role in localizing and activating Nox proteins, in order to establish polarity of fungal hyphal cells during the infection to host plants.