Ribosomal S6 kinases 2 mediates potato resistance to late blight, through WRKY59 transcription factor

Potato late blight is the most devastating pre- and post-harvest crop disease in the world, which is widespread and difficult to control, causing serious economic losses. Cultivating resistant varieties is a major way to prevent and control late blight in a green way. However, due to the rapid evolution of pathogens, the plant resistance is losing. Therefore, mining effective and durable genes involved in disease resistance is crucial for breeding resistant varieties against late blight. In this study, we took "potato-Phytophthora infestans" as the "host-pathogen" model system to discover the potential disease resistance-related genes and elucidate their molecular functional mechanism. Through yeast two-hybridization, bimolecular fluorescence complementation, Co-immunoprecipitation assays, and gene function validation etc., we found that ribosomal protein S6 kinase 2 (StS6K2) is a key resistant protein, which is interacted with StWRKY59 transcription factor. Overexpression of StS6K2 and StWRKY59 both enhanced the plants resistance to P. infestans, and promoted the host immune response, such as ROS burst and callose deposition. In OEStWRKY59 lines, DEGs involved in secondary metabolites synthesis, plant hormone signaling transduction and plant-pathogen interaction were significantly enriched. These findings provide novel genetic resources for the breeding of resistant varieties.