Dissection of the Plant Hormone Signal Transduction Network in Late Blight Resistant Potato Genotype SD20 and Prediction of Key Resistance Genes.

Hormones play an important role in plant disease resistance and defense. Transcriptome data of late blight resistant potato genotype SD20 treated by ethylene (ET), jasmonate (JA), salicylic acid (SA), and Phytophthora infestans CN152 was analyzed to assess the role of the ET/JA/SA regulatory network in plant disease resistance and defense and predict key resistant genes. The results show that there was significant crossover of differentially expressed genes (DEGs) between all treatments, and common and specific plant disease interaction genes for the ET, JA, and SA treatments were differentially expressed in the CN152 treatment. The resistance and defense genes of the potato genotype SD20 could be induced to regulate metabolic and hormone signaling pathways by alternative splicing in all treatments. Further analysis found that JA and ET pathways can work together synergistically, JA/ET and SA pathways antagonize each other to initiate the expression of calmodulin-domain protein kinases (CDPK), calmodulin/calmodulin-like (CaM/CML), and RPM1-interacting protein 4 (RIN4) genes, and activate HSP-mediated HR response and defense-related genes. Meanwhile nine defense genes, including wound-responsive AP2 like factor, glutathione-s-transferase, serine/threonine-protein kinase BRI1, and Avr9/Cf-9 rapidly elicited protein genes were obtained using WGCNA, which provided reliable targets for functional verification. This study provides a theoretical reference for the comprehensive application of plant hormones to improve resistance to potato late blight disease.