Combined transcriptome and metabolome analysis of strawberry fruits in response to powdery mildew infection

Powdery mildew is a common and important fungal disease that influences strawberry (Fragaria x ananassa Duchesne ex Rozier) production. Understanding the interaction between crops and pathogens is essential for managing powdery mildew. In this study, transcriptomic and metabolomic methods were used to analyze the differential genes and metabolites and their correlation to the powdery mildew infection. A total of 22,124 genes were obtained, and the differentially expressed genes (DEGs) at three different developmental stages were determined. Genes involved in plant-pathogen interactions, carbon metabolism, and photosynthesis were upregulated in powdery mildew infected plants. In addition, 162 compounds were detected in ripe strawberry fruits, and the differential metabolites were mainly amino acids (two types), phenols (three types), flavonoids (six types), carbohydrates (three types), and acids (five types). The order-reduction analysis of these substances revealed that the most influential factor was quercetin, which was downregulated in the infected groups. The results provide a reference for developing disease-resistant strawberry plants.