Email: zhenghongyuan@henau.edu.cn

Wheat is one of the most important food crops in the world. Increasing wheat yield is essential for maintaining global food security. Powdery mildew (PM) is a worldwide fungal disease seriously harming wheat production. There is an urgent need to breed PM resistant varieties to ensure stable wheat production.

Chitinases are ubiquitous defense proteins in plant immunity against pathogen invasion. However, their regulation by plant and pathogen factors remains poorly understood. Here we identified a wheat ERF transcription factor (TF) that was rapidly upregulated by powdery mildew infection, which enhanced plant defense by promoting the transcription of multiple chitinase genes.

However, the protein abundance of the ERF TF declined as powdery mildew infection progressed. An E2 enzyme produced by PM interacted with the ERF and mediated its degradation through recruiting a wheat E3 ligase.

Consistent with the above findings, wheat resistance to PM was elevated in the plants overexpressing the ERF TF or with the co-opted E3 ligase downregulated by gene silencing. In sum, our work sheds light on dynamic regulation of chitinase-based plant defense by both host and pathogen genes and provides new molecular targets for engineering wheat resistance against PM through biotechnology breeding.